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Running Head: HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 0
How Survey Method Affects Direct-Spending Reports
Anthony J. Finch
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 1
Abstract
This study examined the influence of survey method on direct spending reports at 3 Virginia
sporting events. Respondents were allocated to 3 survey groups: (1) online, (2) in-person, and
(3) online plus in-person. Statistical analysis found that survey method introduced bias to
respondents’ spending estimates, but this bias did not fully account for all differences observed
between survey methods. Consequently, an undefined demographic difference also existed
between the online and in-person groups. The data suggests that future economic impact studies
of sporting events should use both survey methods to minimize bias.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 2
Introduction
From mega-events such as the Olympics and FIFA World Cup to smaller-scaled local events
like marathons, event-planners frequently encounter questions regarding the return that local
economies can expect for hosting sporting events. These events frequently incur very large
investments, which are sometimes difficult to quantify and track (Li & Blake, 2009). Since local
taxpayers sometimes assume the financial burdens of hosting the event (such as construction of
new facilities, grants awarded to the hosting organization, etc.), local governments frequently
require studies to be performed to verify that there is a positive return-on-investment. Of
particular concern in such analysis is the amount of ‘new’ money that can be brought into the
local economy by such events, where new money is defined as money brought to the local
economy by non-local tourists that would not have visited if not for the event in question.
To effectively measure these effects, economic impact studies typically collect survey data
from visitors attending the event. These data usually include estimated spending across several
different categories, distances travelled to and from the host location, and whether the event in
question was the primary reason for the visit, along with demographic questions (Crompton, Lee,
& Shuster, 2001; Mondello & Rishe, 2004). These figures are then used to infer the direct
spending of all new visitors the event brought to the economy, which in turn are applied to
models to predict the total economic impact of the event on the economy. These models have to
account for a number of complexities, since this direct spending induces more local spending by
local businesses, which do so again, causing a propagation effect that can significantly increase
the economic impact of such an event (Crompton, Lee, & Shuster, 2001). Some have questioned
this process, especially in large events, citing evidence that induced spending is distributed over
a larger region than that which is making the direct investment in supporting the event (Mills &
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 3
Rosentraub, 2013). If so, such regional substitution could substantially impact the returns
observed by the region actually hosting the event.
Regardless of any substitution effects, however, economic impact studies for these events
require surveys that can estimate event-induced spending with a certain degree of accuracy.
Typically, survey data of this sort is collected in-person on pen-and-paper surveys, either at the
event or, for mega-events, as tourists leave the area from airports or other public long-distance
transportation nodes; however, researchers have recently begun using online surveys more and
more (Case & Yang, 2009; Case, Dey, Lu, & Schwanz, 2013; Dolnicar, Laesser, and Matus,
2009). Online surveys have been shown to have several advantages, including significantly
reduced administration costs, but concerns have arisen about whether or not online surveys
generate results that are comparable to those produced by other survey methods (Ward, Clark, &
Zabriskie, 2012; Dolnicar, Laesser, & Matus, 2008).
Several recent studies have examined the advantages of online survey methods, and their
research has revealed a plethora of benefits of using online over in-person surveys, including
reduced costs and time investments (Dolnicar, Laesser, & Mattus, 2008; Ward, Clark, Zabriskie,
& Morris, 2012). However, despite these advantages, concerns over the consistency of data
between survey methods have rightly been drawn into question, as a number of studies have
yielded very different results across survey methods (Case, Dey, Lu, Phang, & Schwanz, 2013;
Case & Yang, 2009; Dolnicar, Laesser, & Matus, 2008) .
Review of Literature
Large-scale events like the Olympics and FIFA World Cup are often studied for their impact
on the local economies, and these studies are often dependent upon in-person survey
information. For example, Lee and Taylor used in-person surveys for their estimates of spending
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 4
at the 2002 World Cup (2005). In other instances, economic impact studies of large events use
national or local tourism information gathered by governmental bodies to estimate spending by
out-of-town tourists, such as in the case of Blake, who used statistics from the United Kingdom’s
Office for National Statistics (2005). Otherwise, as noted by Blake, these large-scale economic
impact studies simply fail to “provide the visitor spending estimates that the results are based
on.” Of course, this makes it difficult to comment on the quality of input data for such studies,
but in the case of Office for National Statistics, it may be noted that all data is, and always has
been, collected from using in-person, paper-and-pencil surveys (2005; 2013). In short, it can be
confidently stated that a significant body of economic impact research is dependent upon in-
person surveys of travel expenditures.
Reliance of such studies upon surveys has spawned a large body of research into the
dependability of these survey methods, some of which has supported the hypothesis that, in the
case of economic impact studies, survey method may not affect results. Olberding and Cobb
(2007) didn’t observe statistically significant differences in responses to online versus telephone
surveys, and went so far as to state that online survey methods were reliable “when there is
strong evidence that the population of interest utilizes email” (p. 29). Ward, Clark, Zabriskie,
and Morris (2012) found that college students were more willing to truthfully answer certain
highly personal survey questions in the online format than in the paper-and-pencil format, but
observed that the actual differences produced in most data would be “minimal at best in actual
interpretation of the data” (p. 522). Since it’s unlikely that direct spending estimates would fall
into the category of questions in which they observed these differences, it’s unlikely that there is
any important effect stemming from perceived anonymity in online surveys.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 5
Further results, however, seem to indicate that significant differences may stem from survey
methods. Case, Dey, Lu, Phang, and Schwanz (2013) observed significantly higher direct
spending estimated collected from in-person surveys than online ones, although Case and Yang
(2009) observed precisely the opposite effect (although in both cases these effects were
statistically significant). Dolnicar, Laesser, and Matus (2008) found that the populations that
preferred mail surveys and that preferred online surveys were nonhomogeneous, although they
were equally unrepresentative of the target population (according to census data); however, they
also found that online surveys yielded superior data (lower dropout rate and fewer omitted
questions). They cautioned, though, that their study was taken from a highly technologically-
inclined population, and therefore may be unrepresentative of the population as a whole. In
addition, it did not test consistency of direct spending estimates between the two survey methods.
An unpublished, preliminary study by Case, Dey, Finch, Springman, and Sekhar in 2013 of
13 sports events conducted between 2008 and 2011, all involving in-person and online portions,
resulted with convincing evidence that the two methods would not produce similar results. Of
the 13 events, all of the observed online spending report averages were lower than their in-person
counterparts. A paired T-test on these data was performed (omitting a single point because it
was significantly affecting variance), yielding a p-value of less than 0.005; when a Wilcoxon
Signed-Rank test was performed to include the one excluded point, the resulting p-value was less
than 0.001. Furthermore, the only demographic difference between the populations was age,
although this difference was modest at most, with online survey methods showing slightly higher
proportions of individuals under 29 years of age and in-person survey methods showing slightly
higher proportions of individuals over 60 years of age. This study, along with evidence cited
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 6
above, provided evidence that survey method would significantly affect the results of economic
impact studies.
In the past, studies have attempted to correct bias in survey data by weighting along certain
parameters that may be more representative of the actual target population, such as in the case of
Leeworthy, Wiley, English, and Kriesel (2001), who note that “Constructing weighted averages
to account for differential sampling across strata in survey research is a common practice” (p.
96). However, since preliminary results seemed to imply that there are not significant
demographic differences between sample populations, weighting along certain population
parameters may be unwarranted and unhelpful.
In lieu of that methodology, this study has been constructed to investigate whether survey
respondents, on average, will respond according to a consistent pattern of relative over- or
underestimation. If so, then it may be possible to construct a heuristic to translate between the
two survey methodologies, and therefore to compensate for the relative bias between survey
methods.
Purpose of This Study
This study was designed to allow for the examination of the relative bias in direct spending
reports between survey methods. By splitting potential respondents into three groups (those
responding to in-person, online, and both in-person and online survey methods), we can observe
the effects of survey method independent of variance introduced by differing respondents and
possibly create a heuristic that would allow for hypothetical conversions between the two
methodologies.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 7
Data Cleaning
Data entered in surveys, especially online surveys, often contains errors that would render it
unusable unless cleaned properly. Such errors include data that is entered as words instead of
numbers, numerical entries that are entered as ranges instead of solid estimates, or responses
such as “could not remember.” For this study, unusable data was cleaned to allow its use. Any
individuals that did not answer direct spending questions or that indicated that they lived in the
area where the event was held were not used for this analysis, as they would inevitably skew the
data. Data that was entered as a range instead of a single number was averaged (for example, an
entry of “150-200” was considered to be “175”), and data entered in the form of words was
directly translated to a numerical entry. In several cases, individuals took the same survey
multiple times. Often, these data were identical, but there were slight variations in several
instances. In such cases, whichever data set was more complete was used; if both were
complete, but used slightly differing numbers, these were averaged.
In one case, an individual responding to the online survey for the Crawlin’ Crab event entered
spending on retail shopping to be $300,125 but did not respond to the next question. This data
was not in line with the rest of the subject’s spending estimates, so it was assumed that the
respondent intended to indicate that spending on retail shopping was $300 and spending on
transportation was $125. In addition, one online response to the Lacrosse tournament data to the
Transportation category was entered as 11000; it was assumed, based on the respondent’s other
entries (which all had been entered with a “.00” at the end), that the respondent intended to enter
110.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 8
Results
XTERRA 2014 East Coast Championships
The XTERRA 2014 East Coast Championship series of races was held in Richmond, VA, in
June 14th and 15th, 2014. 93 individuals responded to the in-person survey; 106 individuals
responded to the online survey. Of the 93 individuals that responded to the in-person survey, 58
provided email addresses and agreed to participate in the follow-up study that was performed;
however, only 22 individuals were able to be identified and their results paired. This was, in
part, due to a large number of individuals that filled out the follow-up survey, but did not provide
the same email address as they did in the original (in-person) survey.
Among respondents to both surveys, “Lodging” was the only individual category that had a
significant p-value for a difference in spending (with a p-value of 0.0096), but Total spending
also demonstrated a significant difference (with a p-value of 0.0123). In addition, variance ratio
tests resulted in significant p-values for the Food, Retail, Transportation, Tourism, and
Entertainment categories. A full table of results is available in Appendix A: Results from the
2014 XTERRA East Coast Championship.
Data from respondents that only responded to one survey method resulted in only one
significant p-value on t-tests between online and in-person means (Tourism), and one p-value
approaching significance (Entertainment, with a p-value of 0.0988). Variance ratio tests were
significant in all categories except the Lodging, Other and Total categories, although the Total
category had a p-value that was very close to significance (with a level of 0.0581).
Shapiro-Wilk tests for Normally-distributed residuals resulted in all significant p-values.
Breusch-Pagan test for heteroskedasticity were significant in the Retail and Tourism categories,
although the Food category was very close to significance (at a value of 0.0680). Influential
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 9
points were observed in the Food, Retail, Transportation, Entertainment, Other, and Total
categories. Both the Entertainment and Other categories had 2 influential points. Notably, one
respondent accounted for 5 out of the 8 total influential points. We have omitted this
individual’s responses in the forthcoming analysis to prevent contamination of more normal data.
This, combined with the Shapiro-Wilk tests and a theoretical reasoning for consistent
heteroskedasticity, also prompted us to use robust standard errors for the remainder of our
analysis.
Once the single respondent with consistently influential responses was removed, paired t-tests
resulted in reasonably similar results; however, variance ratio tests resulted in only 2 significant
values (Food and Tourism, with Other approaching significance), as opposed to 5 previous to the
respondent’s removal.
A series of linear regressions was created, forcibly omitting a constant, and their coefficients
were tested against the constant 1 to test for a 1-to-1 correspondence between results. Of these,
only the Lodging, Other, and Total categories resulted in significant p-values. None of the other
p-values would have been significant at even the 0.1 significance level. Additionally, normal
(unforced) robust linear regressions were created for each category. Significant p-values were
observed on ANOVA tests for the models for the Food, Lodging, Transportation, and Total
categories, although there was one influential point in the Transportation category that
dominated the model; when this point was omitted, the ANOVA resulted in a non-significant p-
value.
A comparison between the surveys of individuals that only responded to the online survey
and online portion of individuals that responded to both survey methods revealed strong
consistency between the two groups. None of the T-tests on the means had a significant p-
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 10
value, and only one variance ratio test had a significant p-value. On the other hand, there were
strong dissimilarities between survey results for individuals that responded only to the in-person
survey and results for those that agreed to participate in the follow-up survey online. Comparing
the two groups with T-tests yielded 4 significant p-values (Retail, Transportation, Tourism, and
Total) and 2 near-significant p-values (Food and Entertainment, with p-values of 0.0530 and
0.0707 respectively). Similarly, all variance ratio tests except that for the Other category had
significant p-values.
When the in-person group was divided between those individuals that agreed to participate in
the follow-up survey and those that refused to do so (regardless of whether or not they did so),
only one p-value for T-tests is significant at the 0.05 level (Lodging); however, 3 others are
significant at the 0.1 level (Retail, Tourism, and Total). Variance ratio tests between the same
groups result in significant p-values for all except the Transportation and Entertainment
categories.
T-tests performed on the in-person surveys of those who agreed to participate in the follow-up
survey and did so compared to those who agreed to do so and did not revealed only one
significant p-value (Transportation), and only one other p-value nearing significance
(Entertainment, with a p-value of 0.0915). Variance ratio tests, however, were significant for all
categories except for Lodging.
Beach Bash Lacrosse Tournament 2014
The Beach Bash Lacrosse Tournament was held June 22nd and 23rd, 2014, in Virginia Beach,
Virginia. 176 individuals responded to the in-person portion of the survey, with 44 providing
email addresses and agreeing to participate in the follow-up online survey; 18 responded to the
online follow-up, although one individual did not provide a matching email address, forcing that
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 11
data to be discarded. Unfortunately, the event organizer neglected to send out the online survey
for those that didn’t take the in-person survey; for this reason, the forthcoming analysis does not
have a general ‘online-only survey respondent’ group. In addition, for the Tourism,
Entertainment, and Other categories, there were not enough nonzero responses to perform a
proper analysis of the data provided by subjects that responded to both survey methods.
Paired T-Tests between in-person and online spending reports of individuals that responded to
both surveys yielded only one significant p-value, in the Entertainment category. No other
categories would have been significant at the 0.1 significance level. Additionally, no variance
ratio tests yielded significant p-values. Breusch-Pagan tests for heteroskedasticity yielded two
significant p-values, in Lodging and Retail, although Shapiro-Wilk tests for Normal residuals
yielded no significant p-values. A full summary of test results is available in Appendix B:
Results from the 2014 Beach Bash Lacrosse Tournament.
There were 2 influential observations for the Lodging category, 3 for Retail, 2 for
Transportation, and 2 for the Total category. None of these points was consistently influential.
In addition, many were influential solely because they constituted one of the few nonzero
responses received in a certain category.
A series of correlations was created with a forced constant of 0, and then tested against the
null hypothesis that the correlation coefficient was 1. None of these tests produced a significant
p-value, or a p-value approaching significance. Additionally, unforced linear regressions with
robust standard errors were created to analyze the relationships between each of the groups.
ANOVA tests on these models produced only 2 significant p-values, in the Lodging and Total
categories.
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In order to verify that the group of respondents that took both surveys was representative of
the entire population, T-Tests and variance ratio tests were performed on each category between
these two groups. Ultimately, 4 categories yielded significant p-values on their T-Tests (Retail,
Transportation, Other and Total), and 3 categories yielded significant p-values on their variance
ratio tests (Retail, Transportation, and Other). An analysis of those that provided an email
(thereby agreeing to take the follow-up, regardless of whether the individual proceeded to do so
or not) compared to those that did not yielded 2 significant p-values on T-Tests (Entertainment
and Total), although 2 others (Food and Transportation) would have been significant at the 0.1
significance level. Variance ratio tests between these two groups yielded 4 significant p-values
(Transportation, Entertainment, Other, and Total), and another that was nearing significance
(Lodging).
A similar analysis of those that agreed to participate in the follow-up survey and those that
actually did produced only one significant p-value among the T-Tests (Retail), although the
Retail, Tourism, Entertainment, and Other categories all yielded significant p-values for variance
ratio tests.
Crawlin’ Crab Half-Marathon 2012
The online survey distributed by the event staff did not include an Other spending category;
however, the post-event survey exclusively for individuals that agreed to participate in the
follow-up survey did include this category, as did all of the in-person surveys. In addition, the
response rate of individuals that agreed to participate in the follow-up that actually did so was
very high. Therefore, there was not a large enough sample of individuals that agreed to
participate, but neglected to do so, to warrant an investigation comparing that group to those that
did participate in the follow-up or to individuals that didn’t provide any email address at all.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 13
Paired T-Tests on each spending category between the data provided by individuals that
responded to both survey methods yielded 3 significant p-values. These were in Lodging,
Transportation, and Total spending. None of the other categories had p-values approaching
significance, and all three had higher averages reported online than in-person. Variance ratio
tests only yielded two significant values, in the Transportation and Total categories, which both
demonstrated higher variance in online spending reports than in-person ones.
Breusch-Pagan Tests for heteroskedasticity yielded significant values in all categories except
for the Lodging and Other categories; in addition, Shapiro-Wilk tests for Normal Residuals
yielded p-values that were all significant at the 0.001 level. There was 1 influential observation
for the Food, Tourism, Entertainment, Other, and Lodging categories, and 2 for the Total
category. Only one point was consistently influential. This point was not removed for further
analysis because the size of the sample was much larger than data gathered at the previously
mentioned events.
Tests of Regression Coefficients from regressions with forced 0 constants against the constant
1 resulted in only 2 significant p-values; these were in the Entertainment and Other categories,
which were both significant at the 0.01 significance level. ANOVA tests performed on unforced
linear regressions using robust standard errors for all categories resulted in only 1 non-significant
p-value, in the Entertainment category. This regression had a p-value of 0.1748. All regressions
and associated ANOVA tests are available in Appendix C: Results from the 2012 Crawlin’ Crab
Half-Marathon.
T-Tests of in-person responses between individuals that responded to both survey methods
and those that only responded in-person yielded only 1 significant p-value, in Entertainment.
Transportation was the only other category approaching significance, with a p-value of 0.0922.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 14
Variance ratio tests on the same categories were all significant except for the Lodging category,
which had a p-value of 0.0605.
As mentioned above, there was no ‘Other’ spending category included in the online survey; it
is therefore omitted from the ‘Total’ category in the forthcoming analysis. Among online
respondents, those who responded to both survey methods exhibited significantly differentiated
spending from those that responded only to the online survey in only the Tourism category. The
Entertainment category was approaching significance, with a p-value of 0.0729. Variance ratio
tests were significant in every category except for Lodging, which had a p-value of 0.2861.
For those individuals that responded to only one survey method or the other, significant
differences between the means of online and in-person respondents were observed in every
category except Retail and Transportation, and the Retail category was approaching significance
with a p-value of 0.0774. Variance ratio tests also were significant in all categories except for
‘Food.’
Tests on All Respondents to Both Surveys
Wilcoxon Signed-Rank tests performed on each category yielded no significant p-values.
Regressions were performed on each category of spending using dummy variables to represent
the different events and dummy variables multiplied by the in-person result to find the effects of
each event separate from the others. These regressions resulted in significant event-specific
regression coefficients for the Food, Lodging, Tourism, and Entertainment categories.
The “Food” category exhibited significant p-values for all coefficients except the coefficient
on in-person reports of spending on food at the Crawlin’ Crab event; however, this coefficient
was approaching significance, with a p-value of 0.081. The Lodging category exhibited a single
significant p-value among the dummy variables; this was on spending at the XTERRA event.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 15
The regression on the Tourism category yielded a significant p-value in both dummy variables
involving the Crawlin’ Crab event (the constant and spending at the Crawlin’ Crab event). The
entertainment regression exhibited a single p-value, on the Crawlin’ Crab constant.
Discussion
Several complications arose in the analysis of the results, which were addressed before any
interpretation was attempted. In the case of the XTERRA event, one influential point was
excluded from a large portion of the analysis. This was necessary because of the relatively small
sample size involved; simply using robust standard errors was insufficient to deal with this.
Comparatively, a number of influential points were left alone in the Crawlin’ Crab event because
the sample size was much larger. In addition, a certain amount of caution should be used when
viewing spending reports in the Tourism, Entertainment, Retail, and Other categories, since there
were very high proportions of 0 responses to these categories. These responses likely affected
the results observed, and also reduced the effective sample sizes considerably. Also, as
mentioned above, the event staff from the Beach Bash event neglected to send the online survey
to the event’s attendees. Fortunately, online surveys were sent to in-person respondents that
agreed to participate in the follow-up survey, allowing the forthcoming analysis to include at
least that portion of data collected from the event.
Among respondents to both surveys, paired T-tests yielded six significant p-values. The
Lodging and Total categories were both differentiated in the XTERRA and Crawlin’ Crab
events. In addition, the Entertainment category was differentiated in the Beach Bash event and
the Transportation category was differentiated in the Crawlin’ Crab event. Tellingly, both of the
events in which Lodging was significantly differentiated were also significantly differentiated
along the Total category in the same direction (i.e. that, if Lodging estimates were higher in-
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 16
person, then Total estimated spending was also higher in-person). In addition, Lodging estimates
given during the online survey for the Beach Bash event were also greater than their in-person
counterparts, although these numbers were not significantly differentiated. It should also be
noted that, in both cases, online estimates for spending on Lodging were greater than their in-
person counterparts.
Although this data is by no means conclusive, it does suggest that the Lodging category may
play a significant role in the differentiation between total spending reports given in-person and
online. Especially given the average size of respondents’ reported spending on Lodging
compared to other spending categories, this relationship seems as though it could be a key
differentiator between the two methodologies. Unfortunately, this is not corroborated by data
from individuals that responded to only one survey or the other. While the Crawlin’ Crab’s
online respondents reported significantly higher spending on lodging than their in-person
counterparts, the XTERRA event yielded precisely the opposite results (although these numbers
were not significantly differentiated, with a p-value of about 0.17). In addition, this would not
explain why preliminary research showed in-person respondents consistently reporting higher
spending than online respondents.
Furthermore, a series of Wilcoxon Signed-Rank tests on paired spending reports for each
category yielded no significant p-values. In fact, none of these tests had a p-value below 0.5.
This evidence gives relatively strong indication that a consistent trend does not exist for
individuals to give higher estimates for one survey method when compared to the other.
Additionally, regressions with forced constants of 0 resulted in only two regression coefficients
that were significantly differentiated from 1, and these were both from the Crawlin’ Crab half-
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 17
marathon. With all of these results combined, it is difficult to say with any certainty that the
survey method is truly inducing different responses when respondents are kept constant.
Because of this, it is very difficult to even begin creating a heuristic that may allow for the
conversion between online and in-person responses. Even if it were possible to do so
consistently within a single event, such a heuristic would be unlikely to be globally applicable,
given the inconsistency of results between the different events and the number of dummy
regression coefficients that were significantly differentiated from 0 in the large regressions on all
respondents to both surveys.
In looking at the possibility that individual heuristics may be used for specific events, this
study looked at a number of regressions on spending estimates between the two survey methods
while holding respondents constant. Conventional linear regressions using robust standard errors
on each of the categories in each of the events resulted in 9 significant p-values on the regression
coefficients (10, if the XTERRA event’s “Transportation” regression is counted, despite its
influential point). This gives a reasonably strong indication that the two surveys are correlated.
Still, there is not enough evidence to say that these regressions could be used as heuristics that
would enable conversion between online and in-person surveys, especially since there may be
other factors at work (as discussed below).
Since there was no online-only group available from the Beach Bash event, there were only 2
events to compare the results of online-only and in-person-only respondents. These results
conflicted, with the two being significantly differentiated along 5 of 7 categories of spending in
the Crawlin’ Crab event and being significantly differentiated along only 1 of the 8 categories of
spending. Coupled with preliminary data mentioned above, this suggests that the survey
methods are not equivalent in a significant number of cases. Thus, there is a certain discrepancy
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 18
present in the data. While respondents to both surveys exhibited some limited differentiation
between survey methods, these differences are not as significant as differences between general
online-only and in-person-only data would suggest. This suggests that there may be another
element at work, in addition to the survey method directly affecting individual respondents’
spending reports.
In order to explain this apparent discrepancy, a number of additional tests were performed to
examine whether or not the survey respondents that agreed to participate in both parts of the
survey were truly representative of both of the populations. Surprisingly, there were a large
number of significant p-values in tests between in-person responses of those individuals that
participated in the follow-up study and responses from those that did not do so. In all, there were
9 significant p-values among these tests, although only 1 of these came from the Crawlin’ Crab
event. Since only 24 of these tests were performed, this is a large enough proportion to warrant
attention, and it seems clear that there is some kind of correlation at work. Interestingly, these
results were not mirrored in the online responses, which had no significant p-values for T-tests
between online responses from respondents that only took the online survey and those that took
both surveys. This should be tempered by the fact that there was no online-only group for the
Beach Bash event, but it is still an important finding.
These findings were, however, somewhat difficult to explain. Preliminary studies indicated
that there should not be significant differences in the demographics of the in-person and online
populations, yet the present results suggest that some kind of difference likely separates those
that agree to participate in the follow-up survey from those that don’t, but no such difference
exists between the former and the online group as a whole. Although online literacy seems a
likely candidate at first, this would not make sense, since all participants in the events had email
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 19
addresses that they provided to the event coordinators when they signed up for the events (which
was how online surveys were distributed after the event). In short, it seems as though there is
some demographic difference between the groups for which preliminary research did not
account, but this unforeseen element cannot be identified without further investigation.
Variance ratio tests were performed in almost every instance that T-tests were. The vast
majority of these tests were significant, indicating that the distributions arising from these
various categories and survey groups may not have been similar, even in cases where their means
were alike. Although an in-depth examination of the distributions arising from responses to
various survey methods is difficult to construct based solely on averages and variance-ratio tests,
these tests suggest that even survey groups that seem relatively similar based upon their averages
and T-tests may, in fact, be produced by very different populations with very different
distributions.
Conclusion
This study yielded a number of significant findings, despite its failure to find a consistent
heuristic that could translate between online and in-person responses to direct spending reports at
sporting events. Unpublished preliminary results suggesting that in-person responses should be
consistently higher than their in-person counterparts were supported, but seem unlikely to be due
solely to respondents’ propensity to answer survey methods differently. It appears as though the
groups of individuals that respond to each of the survey methods may not be entirely consistent.
This conclusion contradicts preliminary research that suggested that the two groups should be
demographically consistent. It remains unclear how the two groups may be differentiated.
A heuristic translator between the two survey methods may still be viable, but would require
multiple parts. If this demographic factor can be identified, weighted averages can be used to
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 20
account for these differences in the same manner as Leeworthy, Wiley, English, and Kriesel in
2001. Once such a method is applied, it may or may not be necessary to use a regression to
account for bias introduced by the survey methods to individual spending reports. If so, present
results suggest that such heuristics will likely be applicable only to the event from which they are
generated. It will be difficult to determine which survey method more accurately represents the
target population (all event-goers), but identifying what truly separates the groups could suggest
what each of the survey methods may be misrepresenting. This would be invaluable in future
researchers’ analyses, allowing them to more accurately portray spending induced by sports
events.
Regardless of the reasons, the results suggest that online and in-person survey methodologies
are not equivalent. This is an important finding, since previous research has yielded conflicting
results. Therefore, future researchers conducting direct spending surveys should gather both
online and in-person data and analyze these data separately. This would eliminate the relative
biases of each method, for insignificant additional cost when compared to the costs of
conducting only an in-person survey. Some surveyors conducting online-only surveys may elect
not to conduct both surveys, however, because of the relatively large additional costs associated
with the in-person data collection. Given the apparent propensity for online spending report
averages to be lower than in-person averages, this seems to be more prudent, at least, than using
only the in-person surveys since results will likely be lower (and thus less prone to
overestimation, at least relative to in-person surveys).
In sum, this study supports the claim that online and in-person survey methods yield
significantly differentiated results and suggests that further research into the demographics of
respondents to these two survey methods is necessary. Until the nature of these differences
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 21
becomes apparent, results from this study indicate that future research using direct spending
reports should acquire such reports from both survey methods and keep them separate during
analysis. Since most studies of direct spending reports are conducted to facilitate cost-benefit
analyses, it seems prudent for researchers that cannot use both methods to use online spending
reports because of their propensity to underestimate spending when compared to in-person
reports. The present results suggest that this would lead to more conservative spending
estimates.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 22
References
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Case, R., Dey, T., Lu, J., Phang, J., & Schwanz, A. (2013). Participant spending at sporting
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Leeworthy, V., Wiley, P., English, D., & Kriesel, W. (2001). Correcting response bias in tourist
spending surveys. Annals of Tourism Research, 83-97.
Li, S., & Blake, A. (2009). Estimating Olympic-related investment and
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Mills, B., & Rosentraub, M. (2013). Hosting mega-events: A guide to the evaluation of
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Mondello, M. J., & Rishe, P. (2004). Comparative economic analyses: Across cities, events, and
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http://www.ons.gov.uk/ons/rel/ott/travel-trends/index.html
Olberding, D., & Cobb, S. (2007). On-line and telephone surveys: The impact of survey mode on
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exploratory study. Journal of Leisure Research, 44(4), 507-530.
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 24
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 25
Appendix A: Results from the 2014 XTERRA East Coast Championship
Comparisons of Paired Observations from Respondents to Both Surveys
Paired T-Tests
Category Online Mean IP Mean P-ValueFood 135.91 104.32 0.0924Lodging 183.41 155.59 0.0096Retail 35 14.55 0.2133Transportation 77.3 43.64 0.0783Tourism 0.68 1.82 0.4879Entertainment 11.86 10 0.74Other 26.67 28.81 0.9092Total 469.62 357.41 0.0123
F-Tests for Variance
Category Online Std. Dev IP Std. Dev P-ValueFood 121.26 76.41 0.0398Lodging 143.39 122.80 0.4836Retail 89.92 35.01 0.0001Transportation 108.21 66.01 0.0281Tourism 3.20 6.64 0.0015Entertainment 30.91 18.77 0.0268Other 77.03 74.77 0.8911Total 326.90 241.00 0.1706
Breusch-Pagan Tests
Category P-ValueFood 0.0680Lodging 0.1482Retail 0.0000Transportation 0.1996Tourism 0.3562Entertainment 0.0000Other 0.8895Total 0.1820
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 26
Shapiro-Wilk tests for Normal Residuals
Category P-ValueFood 0.00232Lodging 0.00394Retail 0.0019Transportation 0.0001Tourism 0.00000Entertainment 0.02070Other 0.00001Total 0.03566
Tests (as above) with Consistently Influential Point Removed
Paired T-Tests
Category Online Mean IP Mean P-ValueFood 128.09 95 0.0924Lodging 192.14 163 0.0094Retail 17.62 10.48 0.4462Transportation 61.93 40.95 0.1405Tourism 0.71 1.9 0.4885Entertainment 7.67 3.69 0.93Other 15.14 10.18 0.8853Total 425.31 333.95 0.0226
F-Tests for Variance
Category Online Std. Dev IP Std. Dev P-ValueFood 118.44 64.23 0.0086Lodging 140.81 120.69 0.4967Retail 38.87 30.08 0.2596Transportation 82.70 66.40 0.3341Tourism 3.27 6.80 0.0019Entertainment 5.33 3.69 0.1088Other 67.71 44.49 0.0696Total 258.59 219.71 0.4728
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 27
Tests of Regression Coefficients (No Constant) Against 1
Category P-ValueFood 0.124Lodging 0.009Retail 0.179Transportation 0.23; 0.825 (one more influential point
removed)Tourism *****Entertainment 0.437Other 0.000Total 0.097***** There were only 2 nonzero responses in-person and 1 nonzero response online, invalidating this test
Linear Regressions (Outlier Removed)
_cons 3.846753 30.07765 0.13 0.900 -59.10649 66.8 FoodIP 1.307879 .3670719 3.56 0.002 .5395884 2.076169 FoodOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 85.672 R-squared = 0.5030 Prob > F = 0.0021 F( 1, 19) = 12.69Linear regression Number of obs = 21
_cons 11.78148 9.541432 1.23 0.232 -8.188967 31.75193 LodgingIP 1.106512 .0602083 18.38 0.000 .9804941 1.232529 LodgingOnl~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 45.804 R-squared = 0.8995 Prob > F = 0.0000 F( 1, 19) = 337.75Linear regression Number of obs = 21
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 28
_cons 13.9 8.553199 1.63 0.121 -4.002052 31.80205 RetailIP .355 .3791883 0.94 0.361 -.4386503 1.14865 RetailOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 38.355 R-squared = 0.0754 Prob > F = 0.3609 F( 1, 19) = 0.88Linear regression Number of obs = 21
_cons 27.92096 15.62839 1.79 0.090 -4.789643 60.63157TransportationIP .8305346 .1374133 6.04 0.000 .5429253 1.118144 Transportation~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 63.235 R-squared = 0.4446 Prob > F = 0.0000 F( 1, 19) = 36.53Linear regression Number of obs = 21
_cons 36.6254 19.68623 1.86 0.079 -4.733836 77.98463TransportationIP .4787359 .5050194 0.95 0.356 -.5822706 1.539742 Transportation~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 63.783 R-squared = 0.0525 Prob > F = 0.3557 F( 1, 18) = 0.90Linear regression Number of obs = 20
*****One more influential point removed
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 29
_cons .7731959 .7913468 0.98 0.341 -.883112 2.429504 TourismIP -.0309278 .0323158 -0.96 0.351 -.0985656 .0367099 TourismOnl~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 3.3514 R-squared = 0.0041 Prob > F = 0.3506 F( 1, 19) = 0.92Linear regression Number of obs = 21
_cons 3.711314 3.443636 1.08 0.295 -3.4963 10.91893EntertainmentIP .4886023 .5504011 0.89 0.386 -.6634004 1.640605 Entertainment~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 23.575 R-squared = 0.1146 Prob > F = 0.3858 F( 1, 19) = 0.79Linear regression Number of obs = 21
_cons 18.51052 16.34918 1.13 0.272 -15.7087 52.72974 OtherIP -.0941672 .1138435 -0.83 0.418 -.3324444 .14411 OtherOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 67.698 R-squared = 0.0040 Prob > F = 0.4184 F( 1, 19) = 0.68Linear regression Number of obs = 21
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 30
_cons 126.4043 64.84746 1.95 0.066 -9.322979 262.1316 TotalIP .8950676 .1564672 5.72 0.000 .5675781 1.222557 TotalOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 172.27 R-squared = 0.5784 Prob > F = 0.0000 F( 1, 19) = 32.72Linear regression Number of obs = 21
Scatter Plots
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 31
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 32
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 33
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 34
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 35
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 36
Residual Plots
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 37
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 38
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 40
Comparisons of Online-Only and Online Portion of Respondents to Both Surveys
T-Tests
Category Online (Both) Online (Only) P-ValueFood 135.91 131.54 0.8814Lodging 183.41 186.14 0.9413Retail 35 35.01 0.9995Transportation 77.3 77.22 0.9974Tourism 0.68 1.76 0.3496Entertainment 11.86 11.69 0.9819Other 25.45 11.51 0.4370Total 469.62 454.87 0.8642
F-Tests for Variance
Category Online (Both) Std. Dev
Online (Only) Std. Dev
P-Value
Food 121.26 120.60 0.9202Lodging 183.41 186.14 0.1579Retail 89.92 77.40 0.3392Transportation 108.21 96.22 0.4479Tourism 3.20 8.39 0.0000Entertainment 30.91 36.89 0.3620Other 75.39 67.75 0.4872Total 326.90 455.37 0.0870
Comparisons of In-Person-Only and In-Person Portion of Respondents to Both Surveys
T-Tests
Category IP(Both) IP (Only P-ValueFood 104.32 152.67 0.0530Lodging 155.59 200.49 0.1924Retail 14.55 62.85 0.0166Transportation 43.64 105.14 0.0100Tourism 1.82 9.36 0.0182Entertainment 10 29.36 0.0707Other 27.5 17.71 0.5995Total 357.41 577.58 0.0113
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 41
F-Tests for Variance
Category IP (Both) Std. Dev IP (Only) Std. Dev P-ValueFood 76.41 153.99 0.0007Lodging 122.80 181.48 0.0475Retail 35.01 153.13 0.0000Transportation 66.01 155.52 0.0001Tourism 1.42 2.80 0.0000Entertainment 4.00 9.79 0.0000Other 74.77 78.10 0.8564Total 240.10 566.47 0.0001
Comparisons of In-Person Email-Providers and Non-Email-Providers
T-Tests
Category Email No Email P-ValueFood 126.23 165.34 0.2497Lodging 148.37 257.14 0.0056Retail 28.46 88.49 0.0917Transportation 88.04 94.34 0.8274Tourism 4.04 13.29 0.0689Entertainment 27.11 20.86 0.6868Other 17.11 24.86 0.6892Total 439.34 664.31 0.0774
F-Tests for Variance
Category No Email Std. Dev Email Std. Dev P-ValueFood 179.15 109.68 0.0011Lodging 194.90 138.54 0.0230Retail 198.05 69.58 0.0000Transportation 120.58 154.03 0.1283Tourism 26.81 15.42 0.0002Entertainment 70.52 74.04 0.7731Other 106.17 52.65 0.0000Total 679.64 362.78 0.0000
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 42
Comparisons of In-Person Email Providers that Did and Did Not Participate in the Follow-Up Survey
T-Tests
Category Did Follow-Up Didn’t Do Follow-Up P-ValueFood 104.32 140 0.1873Lodging 155.59 143.83 0.7475Retail 14.55 37.21 0.1629Transportation 43.64 115.94 0.0406Tourism 1.82 5.43 0.3082Entertainment 10 37.86 0.0915Other 27.5 10.57 0.3233Total 357.41 490.85 0.1318
F-Tests for Variance
Category No Email Std. Dev Email Std. Dev P-ValueFood 76.41 125.30 0.0196Lodging 122.80 149.14 0.3512Retail 35.01 83.74 0.0001Transportation 66.01 185.22 0.0000Tourism 6.64 18.96 0.0000Entertainment 18.77 92.21 0.0000Other 74.77 31.62 0.0000Total 240.10 416.92 0.0102
Comparisons of Online-Only and In-Person-Only Respondents
T-Tests
Category Online Mean IP Mean P-ValueFood 131.54 152.67 0.3531Lodging 186.14 200.49 0.1708Retail 35.01 62.85 0.1708Transportation 77.22 105.14 0.1942Tourism 1.76 9.36 0.0116Entertainment 11.69 29.36 0.0988Other 11.51 17.71 0.6038Total 454.87 577.58 0.1472
F-Tests for Variance
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 43
Category Online Std. Dev IP Std. Dev P-ValueFood 120.60 153.99 0.0340Lodging 188.28 181.48 0.7560Retail 77.40 153.13 0.0000Transportation 96.22 155.52 0.0000Tourism 8.39 23.39 0.0000Entertainment 36.89 81.93 0.0000Other 67.75 78.10 0.2167Total 455.37 566.47 0.0581
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 44
Appendix B: Results from the 2014 Beach Bash Lacrosse Tournament
Comparisons of Paired Observations from Respondents to Both Surveys
Paired T-Tests
Category Online Mean IP Mean P-ValueFood 179.53 185 0.8524Lodging 249.29 235.29 0.4848Retail 34.33 36.67 0.8665Transportation 92.35 70.88 0.2220Tourism 0 9.41 0.1773Entertainment 0 17.53 0.0528Other 5.88 0 0.3322Total 557.35 553.41 0.9403
F-Tests for Variance
Category Online Std. Dev IP Std. Dev P-ValueFood 88.68 85.81 0.8967Lodging 157.27 172.26 0.7201Retail 43.95 43.57 0.9644Transportation 65.24 58.32 0.6588Tourism 0 27.49Entertainment 0 34.55Other 24.25 0Total 261.77 281.52 0.7746
Breusch-Pagan Tests
Category P-ValueFood 0.8802Lodging 0.0372Retail 0.0351Transportation 0.7667TourismEntertainmentOtherTotal 0.1353
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 45
Shapiro-Wilk tests for Normal Residuals
Category P-ValueFood 0.7040Lodging 0.4463Retail 0.6795Transportation 0.9873TourismEntertainmentOtherTotal 0.8426
Tests of Regression Coefficients (No Constants) Against 1
Category P-ValueFood 0.287Lodging 0.473Retail 0.191Transportation 0.795TourismEntertainmentOtherTotal 0.390
Linear Regressions
_cons 167.1149 51.50369 3.24 0.005 57.33741 276.8925 FoodIP .0671053 .2446414 0.27 0.788 -.4543355 .588546 FoodOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 91.396 R-squared = 0.0042 Prob > F = 0.7876 F( 1, 15) = 0.08Linear regression Number of obs = 17
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 46
_cons 59.42104 43.53538 1.36 0.192 -33.37244 152.2145 LodgingIP .8069606 .1255554 6.43 0.000 .5393455 1.074576 LodgingOnl~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 75.965 R-squared = 0.7813 Prob > F = 0.0000 F( 1, 15) = 41.31Linear regression Number of obs = 17
_cons 23.58511 10.6676 2.21 0.046 .539168 46.63106 RetailIP .2931333 .3337766 0.88 0.396 -.4279471 1.014214 RetailOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 43.467 R-squared = 0.0918 Prob > F = 0.3958 F( 1, 13) = 0.77Linear regression Number of obs = 15
_cons 63.12068 22.57647 2.80 0.014 15.00007 111.2413TransportationIP .4124054 .2592784 1.59 0.133 -.1402334 .9650442 Transportation~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 62.637 R-squared = 0.1359 Prob > F = 0.1326 F( 1, 15) = 2.53Linear regression Number of obs = 17
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 47
_cons 200.5934 131.4421 1.53 0.148 -79.56887 480.7556 TotalIP .6446549 .1843487 3.50 0.003 .2517249 1.037585 TotalOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 194.83 R-squared = 0.4807 Prob > F = 0.0032 F( 1, 15) = 12.23Linear regression Number of obs = 17
Scatter Plots
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 48
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 49
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 50
Residual Plots
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 52
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Comparisons of In-Person-Only and In-Person Portion of Respondents to Both Surveys
T-Tests
Category IP Portion of Both Mean
IP only Mean P-Value
Food 211.29 185 0.2628Lodging 289.16 235.29 0.2355Retail 78.25 35.29 0.0019Transportation 115.89 70.88 0.0324Tourism 13.40 9.41 0.5926Entertainment 15.94 17.53 0.8592Other 2.61 0 0.0163Total 726.53 553.41 0.0296
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 53
F-Tests for Variance
Category IP Portion of Both Std. Dev
IP only Std. Dev P-Value
Food 120.88 85.81 0.1150Lodging 174.48 172.26 0.9739Retail 89.25 43.57 0.0020Transportation 188.55 58.32 0.0000Tourism 38.86 27.49 0.1118Entertainment 34.74 34.55 0.9428Other 13.56 0 0.0000Total 378.66 281.52 0.1716
Comparisons of In-Person Email Providers that Did and Did Not Participate in the Follow-Up Survey
T-Tests
Category Follow-Up IP Mean No Follow-Up Mean P-ValueFood 185 180.56 0.8816Lodging 235.29 285.81 0.3009Retail 35.29 77.81 0.0392Transportation 70.88 91.30 0.2691Tourism 9.41 12.96 0.7666Entertainment 17.53 2.96 0.1107Other 0 1.11 0.3265Total 553.41 652.52 0.2809
F-Tests for Variance
Category Follow-Up IP Mean No Follow-Up Mean P-ValueFood 85.81 109.76 0.3071Lodging 172.26 121.38 0.1090Retail 43.57 87.90 0.0051Transportation 58.32 59.30 0.9700Tourism 27.49 51.1269 0.0124Entertainment 34.55 12.03 0.0000Other 0 5.77 0.0000Total 281.52 309.06 0.7105
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 54
In-Person Email Providers vs Non-Providers
T-Tests
Category Non-Providers Mean Providers Mean P-ValueFood 217.58 182.27 0.0593Lodging 289.84 266.30 0.3836Retail 78.33 61.39 0.2263Transportation 120.92 83.41 0.0617Tourism 13.48 11.59 0.7941Entertainment 18.60 8.59 0.0423Other 2.92 0.68 0.1240Total 741.67 614.23 0.0264
F-Tests for Variance
Category Non-Providers Std. Dev.
Providers Std. Dev. P-Value
Food 122.47 100.14 0.1296Lodging 183.83 143.42 0.0625Retail 89.85 76.27 0.2167Transportation 205.01 59.10 0.0000Tourism 36.09 43.18 0.1276Entertainment 37.22 24.15 0.0016Other 14.65 4.52 0.0000Total 390.67 299.38 0.0462
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 55
Appendix C: Results from the 2012 Crawlin’ Crab Half-Marathon
Comparisons of Paired Responses from Respondents to Both Surveys
Paired T-Tests
Category Online Mean IP Mean P-ValueFood 100.58 93.92 0.4794Lodging 103.66 83.7 0.0430Retail 52.7 47.4 0.5362Transportation 73.62 48.3 0.0062Tourism 8.02 9.8 0.4312Entertainment 9.2 12.1 0.4958Other 18.5 16.3 0.7491Total 366.28 311.52 0.0361
F-Tests for Variance
Category Online Std. Dev IP Std. Dev P-ValueFood 76.89 71.02 0.5801Lodging 114.06 91.93 0.1345Retail 63.92 51.65 0.1391Transportation 63.85 42.19 0.0044Tourism 29.83 25.05 0.2250Entertainment 24.46 23.17 0.7057Other 68.29 68.28 0.9991Total 277.08 204.14 0.0347
Breusch-Pagan Tests
Category P-ValueFood 0.0001Lodging 0.5952Retail 0.0114Transportation 0.0007Tourism 0.0000Entertainment 0.0079Other 0.9054Total 0.0007
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 56
Shapiro-Wilk tests for Normal Residuals
Category P-ValueFood 0.00001Lodging 0.00000Retail 0.00001Transportation 0.00000Tourism 0.00000Entertainment 0.00000Other 0.00000Total 0.00001
Tests of Regression Coefficients Against 1
Category P-ValueFood 0.33Lodging 0.134Retail 0.291Transportation 0.33Tourism 0.952Entertainment 0.001Other 0.002Total 0.133
Linear Regressions
_cons 39.21588 14.61645 2.68 0.010 9.827533 68.60423 FoodIP .6533658 .182121 3.59 0.001 .2871871 1.019545 FoodOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 61.95 R-squared = 0.3642 Prob > F = 0.0008 F( 1, 48) = 12.87Linear regression Number of obs = 50
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 57
_cons 20.22936 12.94724 1.56 0.125 -5.802813 46.26153 LodgingIP .9967819 .0886286 11.25 0.000 .818582 1.174982 LodgingOnl~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 68.626 R-squared = 0.6454 Prob > F = 0.0000 F( 1, 48) = 126.49Linear regression Number of obs = 50
_cons 24.85877 9.47997 2.62 0.012 5.798016 43.91953 RetailIP .5873676 .1955039 3.00 0.004 .1942808 .9804545 RetailOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 56.847 R-squared = 0.2252 Prob > F = 0.0042 F( 1, 48) = 9.03Linear regression Number of obs = 50
_cons 47.30089 17.02815 2.78 0.008 13.06349 81.53828TransportationIP .5449092 .2115611 2.58 0.013 .1195371 .9702813 Transportation~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 60.183 R-squared = 0.1297 Prob > F = 0.0131 F( 1, 48) = 6.63Linear regression Number of obs = 50
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 58
_cons -1.865162 1.187427 -1.57 0.123 -4.252644 .52232 TourismIP 1.00869 .2882939 3.50 0.001 .4290363 1.588344 TourismOnl~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 16.021 R-squared = 0.7175 Prob > F = 0.0010 F( 1, 48) = 12.24Linear regression Number of obs = 50
_cons 6.470376 3.008157 2.15 0.037 .4220702 12.51868EntertainmentIP .2255888 .1637717 1.38 0.175 -.1036964 .5548739 Entertainment~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 24.143 R-squared = 0.0457 Prob > F = 0.1748 F( 1, 48) = 1.90Linear regression Number of obs = 50
_cons 6.286265 6.588198 0.95 0.345 -6.960195 19.53272 OtherIP .7493089 .0659064 11.37 0.000 .6167951 .8818227 OtherOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 45.701 R-squared = 0.5613 Prob > F = 0.0000 F( 1, 48) = 129.26Linear regression Number of obs = 50
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 59
_cons 44.16726 30.45181 1.45 0.153 -17.06021 105.3947 TotalIP 1.034003 .130371 7.93 0.000 .771875 1.296132 TotalOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 181.35 R-squared = 0.5803 Prob > F = 0.0000 F( 1, 48) = 62.90Linear regression Number of obs = 50
Scatter Plots
010
020
030
040
0
0 100 200 300 400FoodIP
Fitted values FoodOnline
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 60
010
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0 100 200 300 400LodgingIP
Fitted values LodgingOnline
010
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0 50 100 150 200RetailIP
Fitted values RetailOnline
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 61
010
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0 50 100 150 200TransportationIP
Fitted values TransportationOnline
050
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0 50 100 150TourismIP
Fitted values TourismOnline
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 62
050
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0 20 40 60 80 100EntertainmentIP
Fitted values EntertainmentOnline
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0 100 200 300 400 500OtherIP
Fitted values OtherOnline
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 63
050
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0 200 400 600 800TotalIP
Fitted values TotalOnline
Residual Plots
-100
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0R
esid
uals
0 100 200 300 400FoodIP
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 64
-100
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esid
uals
0 100 200 300 400LodgingIP
-100
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0 50 100 150 200RetailIP
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 65
-100
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uals
0 50 100 150 200TransportationIP
-100
-50
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idua
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 66
-50
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idua
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0 20 40 60 80 100EntertainmentIP
-100
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uals
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HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 67
-200
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0 200 400 600 800TotalIP
Comparisons of In-Person Only and the In-Person Portion of Respondents to Both Surveys
T-Tests
Category Both Mean Only Mean P-ValueFood 100.58 109.87 0.4514Lodging 103.66 118.27 0.4171Retail 52.7 64.64 0.2577Transportation 73.62 56.42 0.0922Tourism 8.02 13.90 0.2219Entertainment 9.2 19.05 0.0247Other 18.5 5.68 0.1993Total 366.28 387.83 0.6247
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 68
F-Tests for Variance
Category Both Std. Dev Only Std. Dev P-ValueFood 76.89 104.32 0.0106Lodging 114.06 142.28 0.0605Retail 63.92 97.26 0.0006Transportation 63.85 82.41 0.0310Tourism 29.83 41.22 0.0069Entertainment 24.46 47.68 0.0000Other 68.29 36.47 0.0000Total 277.08 361.82 0.0244
Comparisons of Online-Only and the Online Portion of Respondents to Both Surveys
T-Tests
Category Both Mean Only Mean P-ValueFood 93.92 87.25 0.6080Lodging 83.7 71.19 0.4189Retail 47.4 50.09 0.7800Transportation 48.3 51.08 0.7323Tourism 9.8 2.06 0.0378Entertainment 12.1 5.59 0.0729Other*Total** 295.22 266.65 0.4100*Omitted in online-only survey**Omits Other spending for “Both”
F-Tests for Variance
Category Both Std. Dev Only Std. Dev P-ValueFood 71.02 104.2 0.0024Lodging 91.93 104.83 0.2861Retail 51.65 79.07 0.0008Transportation 42.19 69.75 0.0001Tourism 25.05 10.24 0.0000Entertainment 23.17 18.12 0.0245Other*Total** 192.05 271.03 0.0060
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 69
Comparisons of Online-Only and In-Person-Only Respondents
T-Tests
Category Online Mean IP Mean P-ValueFood 109.87 87.25 0.0243Lodging 118.27 71.19 0.0000Retail 64.64 50.09 0.0774Transportation 56.42 51.08 0.4529Tourism 13.90 2.06 0.0000Entertainment 19.05 5.59 0.0000Other*Total** 382.15 266.65 0.0001
F-Tests for Variance
Category Online Std. Dev IP Std. Dev P-ValueFood 104.32 104.20 0.9990Lodging 142.28 104.831 0.0000Retail 97.26 79.07 0.0034Transportation 82.41 69.75 0.0171Tourism 41.22 10.24 0.0000Entertainment 47.68 18.12 0.0000Other*Total** 357.59 271.03 0.0001
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 70
Appendix D: Results from Tests on All Respondents to Both Surveys
Wilcoxon Signed-Rank Tests
Prob > |z| = 0.8288 z = -0.216Ho: FoodOnline = FoodIP
adjusted variance 58930.63 adjustment for zeros -717.50adjustment for ties -93.13unadjusted variance 59741.25
all 89 4005 4005 zero 20 210 210 negative 40 1950 1897.5 positive 29 1845 1897.5 sign obs sum ranks expected
Wilcoxon signed-rank test
Prob > |z| = 0.9672 z = -0.041Ho: LodgingOnline = LodgingIP
adjusted variance 53314.88 adjustment for zeros -6396.25adjustment for ties -30.13unadjusted variance 59741.25
all 89 4005 4005 zero 42 903 903 negative 24 1560.5 1551 positive 23 1541.5 1551 sign obs sum ranks expected
Wilcoxon signed-rank test
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 71
Prob > |z| = 0.5151 z = 0.651Ho: RetailOnline = RetailIP
adjusted variance 50663.50 adjustment for zeros -5135.00adjustment for ties -26.50unadjusted variance 55825.00
all 87 3828 3828 zero 39 780 780 negative 21 1377.5 1524 positive 27 1670.5 1524 sign obs sum ranks expected
Wilcoxon signed-rank test
Prob > |z| = 0.5821 z = -0.550Ho: TransportationOnline = TransportationIP
adjusted variance 57980.25 adjustment for zeros -1732.50adjustment for ties -28.50unadjusted variance 59741.25
all 89 4005 4005 zero 27 378 378 negative 33 1946 1813.5 positive 29 1681 1813.5 sign obs sum ranks expected
Wilcoxon signed-rank test
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 72
Prob > |z| = 0.9761 z = -0.030Ho: TourismOnline = TourismIP
adjusted variance 17871.13 adjustment for zeros -41870.00adjustment for ties -0.13unadjusted variance 59741.25
all 89 4005 4005 zero 79 3160 3160 negative 5 426.5 422.5 positive 5 418.5 422.5 sign obs sum ranks expected
Wilcoxon signed-rank test
Prob > |z| = 0.7057 z = -0.378Ho: EntertainmentOnline = EntertainmentIP
adjusted variance 38396.63 adjustment for zeros -21336.00adjustment for ties -8.63unadjusted variance 59741.25
all 89 4005 4005 zero 63 2016 2016 negative 14 1068.5 994.5 positive 12 920.5 994.5 sign obs sum ranks expected
Wilcoxon signed-rank test
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 73
Prob > |z| = 0.9944 z = 0.007Ho: OtherOnline = OtherIP
adjusted variance 20453.75 adjustment for zeros -37306.50adjustment for ties -0.75unadjusted variance 57761.00
all 88 3916 3916 zero 76 2926 2926 negative 6 494 495 positive 6 496 495 sign obs sum ranks expected
Wilcoxon signed-rank test
Prob > |z| = 0.9788 z = -0.027Ho: TotalOnline = TotalIP
adjusted variance 59726.88 adjustment for zeros -3.50adjustment for ties -10.88unadjusted variance 59741.25
all 89 4005 4005 zero 3 6 6 negative 45 2006 1999.5 positive 41 1993 1999.5 sign obs sum ranks expected
Wilcoxon signed-rank test
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 74
Regressions
_cons 167.1149 50.09744 3.34 0.001 67.47315 266.7567 CRABFOODIP .4902417 .277209 1.77 0.081 -.0611158 1.041599XTERRAFOODIP 1.087231 .3563871 3.05 0.003 .378391 1.79607 Crab -129.2529 51.36262 -2.52 0.014 -231.4111 -27.09471 XTERRA -151.6241 55.69946 -2.72 0.008 -262.4081 -40.84008 FoodIP .0671053 .2379617 0.28 0.779 -.406191 .5404015 FoodOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 71.796 R-squared = 0.4526 Prob > F = 0.0000 F( 5, 83) = 11.43Linear regression Number of obs = 89
_cons 59.42104 42.34669 1.40 0.164 -24.80483 143.6469 CRABLODGINGIP -.1594842 .2069311 -0.77 0.443 -.5710618 .2520934XTERRALODGINGIP .3053392 .1348434 2.26 0.026 .0371411 .5735372 Crab -42.83844 43.84797 -0.98 0.331 -130.0503 44.37341 XTERRA -49.07568 43.13651 -1.14 0.259 -134.8725 36.72111 LodgingIP .8069606 .1221273 6.61 0.000 .5640544 1.049867 LodgingOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 57.391 R-squared = 0.8338 Prob > F = 0.0000 F( 5, 83) = 154.24Linear regression Number of obs = 89
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 75
_cons 20.03747 11.81312 1.70 0.094 -3.466935 43.54187 CRABLODGINGIP .0997575 .0857788 1.16 0.248 -.0709154 .2704305XTERRALODGINGIP -.196258 .1664317 -1.18 0.242 -.5274048 .1348889 Crab -3.525394 13.53121 -0.26 0.795 -30.44826 23.39747 XTERRA 39.8274 44.96576 0.89 0.378 -49.64037 129.2952 RetailIP .3898873 .1924197 2.03 0.046 .0070325 .7727421 RetailOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 55.644 R-squared = 0.2423 Prob > F = 0.0007 F( 5, 81) = 4.76Linear regression Number of obs = 87
_cons 63.12068 21.96004 2.87 0.005 19.44304 106.7983CRABTRANSPORTA~P -.1744513 .3007134 -0.58 0.563 -.7725581 .4236555XTERRATRANSPOR~P .5961501 .3440198 1.73 0.087 -.0880914 1.280392 Crab -32.33885 23.9377 -1.35 0.180 -79.94998 15.27227 XTERRA -29.83037 27.34728 -1.09 0.279 -84.223 24.56226TransportationIP .4124054 .252199 1.64 0.106 -.0892083 .9140191 Transportation~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 58.863 R-squared = 0.3329 Prob > F = 0.0000 F( 5, 83) = 6.57Linear regression Number of obs = 89
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 76
_cons -4.44e-14 . . . . . CRABTOURISMIP .7112766 .0790209 9.00 0.000 .5541072 .868446XTERRATOURISMIP -.0294118 .0303132 -0.97 0.335 -.0897036 .0308801 Crab 4.095562 1.979984 2.07 0.042 .1574533 8.033671 XTERRA .7352941 .7422587 0.99 0.325 -.7410286 2.211617 TourismIP 7.07e-15 4.73e-09 0.00 1.000 -9.40e-09 9.40e-09 TourismOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 10.356 R-squared = 0.7295 Prob > F = 0.0000 F( 5, 83) = 20.15Linear regression Number of obs = 89
_cons 5.68e-14 . . . . .CRABENTERTAINM~P .2024013 .118845 1.70 0.092 -.0339766 .4387792XTERRAENTERTAI~P .877027 .5476212 1.60 0.113 -.2121696 1.966224 Crab 10.23791 3.524716 2.90 0.005 3.227391 17.24843 XTERRA 3.093366 3.496119 0.88 0.379 -3.860274 10.04701 EntertainmentIP -1.10e-15 . . . . . EntertainmentO~e Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 21.809 R-squared = 0.1837 Prob > F = . F( 4, 83) = .Linear regression Number of obs = 89
HOW SURVEY METHOD AFFECTS DIRECT-SPENDING REPORTS 77
_cons 5.882353 5.876096 1.00 0.320 -5.804966 17.56967 CRABOTHERIP .3599774 .4630217 0.78 0.439 -.560954 1.280909XTERRAOTHERIP 0 (omitted) Crab -3.4402 6.263394 -0.55 0.584 -15.89784 9.017438 XTERRA 9.574662 17.67222 0.54 0.589 -25.57467 44.72399 OtherIP .3890954 .2275532 1.71 0.091 -.0634989 .8416896 OtherOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 50.378 R-squared = 0.4158 Prob > F = 0.0954 F( 4, 83) = 2.05Linear regression Number of obs = 88
_cons 200.5934 127.8532 1.57 0.120 -53.70154 454.8883 CRABTOTALIP -.0833973 .2001038 -0.42 0.678 -.4813957 .3146012XTERRATOTALIP .4575169 .2750723 1.66 0.100 -.0895909 1.004625 Crab -94.65079 131.063 -0.72 0.472 -355.3298 166.0282 XTERRA -124.9014 146.7315 -0.85 0.397 -416.7445 166.9417 TotalIP .6446549 .1793153 3.60 0.001 .288004 1.001306 TotalOnline Coef. Std. Err. t P>|t| [95% Conf. Interval] Robust
Root MSE = 162.39 R-squared = 0.6526 Prob > F = 0.0000 F( 5, 83) = 32.38Linear regression Number of obs = 89