an examination into the predictive content of the composite index of leading indicators
TRANSCRIPT
MA Exit Paper Delehunt 0
An Examination into the Predictive Content of the Composite Index of Leading Indicators
Masters Degree Exit Paper Miami University
Sean Delehunt Wednesday, July 28, 2004
MA Exit Paper Delehunt 1
ABSTRACT
This paper sets out to determine from where the Composite Index of Leading Indicators (CLI) derives its predictive power. The inspiration comes from previous research which is discussed in the second section of the paper. Data have been obtained from a variety of sources on key macroeconomic variables, such as output, price level, interest rate, money supply and government spending, as well as the CLI and its ten components spanning from 1959 to 2004. The predictive power of the CLI components is examined both in an overall and marginal sense, through running several regression specifications and testing joint hypothesis. The results suggest that nearly all components currently included in the CLI offer overall predictive power to GDP, and half of these also offer marginal predictive power.
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I. Introduction
Key economic indicators play an important role in understanding business cycles. Of
particular interest are leading economic indicators, which historically peak and trough before
business cycle peaks and troughs. These indicators have the potential to predict economic
recessions and expansions, as well as forecast numerical values of key macroeconomic variables.
Due to their potential predictive power, these indicators are of great economic and political
importance. Leading indicators have been in existence since the Great Depression, and they
were first complied into an index in 1968, using twelve of the most promising indicators. The
Composite Index of Leading Indicators (CLI), as it is known, has evolved over time as a result of
changes in the economy and the effectiveness of included indicators. Originally intended to
predict business cycle turning points, it is also now used to forecast values of important
macroeconomic variables.
This paper sets out to explore the predictive power of the leading indicators within the
CLI with respect to several key macroeconomic variables. In doing so, the history and
importance of leading economic indicators are explored by reviewing key empirical publications
on the topic. Additionally, several issues that arise when using leading indicators will be
illustrated. Once the proper background information is given and the importance established the
paper proceeds in its own empirical study, inspired by previous research, to determine from
where the index of leading indicators derives its predictive power. The structure is as follows.
Section II reviews the previous literature in this area and motivates the analysis of this paper.
Section III outlines the selected data, stationarity tests and variable transformations. The models
are introduced in Section IV and the results are discussed in Section V. Finally Section VI
concludes.
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II. Previous Literature
II. a. Background on Leading Indicators
Leading economic indicators are a product of the Great Depression, created in an attempt
to foresee future economic activity and predict the flow of business cycles. In 1937 at the
request of Treasury Secretary Henry Morgenthau, Jr. members of the National Bureau of
Economic Research (NBER) Wesley C. Mitchell and Arthur F. Burns complied a list of
economic indicators that, in their words “have been tolerably consistent in their timing in relation
to business cycle revivals and that at the same time are sufficiently general interest to warrant
some attention by students of current economic conditions.”1 These leading indicators were
originally developed as a tool to predict business cycle turning points, rather than to forecast
levels of economic output; however their use evolved as econometric methods and computer
technology improved. The management of these leading indicators has also evolved over time.
Starting with the efforts of Mitchell and Burns at the NBER in compiling a list of leading
indicators, these indicators were compiled into an index in 1968 and maintained by the United
States Department of Commerce up to the mid-1990s. Since December 1995, The Conference
Board has been the official source of the CLI, as well as composite indexes of coincident and
lagging indicators. The composition of this index has also changed as more suitable indicators
have replaced those which were less effective.
These leading indicators have been complied into a single index for a variety of reasons.
First, the index provides a summary of the most important leading indicators. Additionally,
individual indicators perform differently depending on the situation; therefore an index of these
various indicators provides a well rounded prediction of economic activity. Also, incorporating
1 Mitchell and Burns 1938, quoted in Moore, 1979, p. 401.
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these series into an index smoothes out the volatility of individual series and allows for good
predictions of the business cycle.
The index is created by taking a weighted average of the individual components and is
currently relative to a base of 100 in the year 1996. The issue of timeliness of data availability
when constructing the CLI is of concern to those who study it. Often times the CLI undergoes
substantial revisions as more accurate data are obtained, however these revisions take time.
Currently the CLI contains data on:
1. real money supply 2. stock prices 3. interest rate term spread 4. consumer expectations 5. new housing starts 6. average weekly manufacturing hours 7. average weekly initial claims for unemployment insurance 8. manufacturer’s new orders for consumer goods and materials 9. manufacturer’s new orders for non-defense capital goods 10. vendor performance
The Conference Board believes these to be the best combination of leading economic data for
predicting business cycles in today’s economy.
In addition to the official Composite Index of Leading Indicators maintained by The
Conference Board, James H. Stock and Mark W. Watson, have proposed additional experimental
indexes which they believe offer more accurate predictions of business cycle behavior. These
indexes are regularly released in the “Stock and Watson Indicator Report.”2 Their work on this
and other in areas is discussed the subsequent subsection.
II. b. Empirical Research with Leading Indicators
Much research has been done in the area of leading economic indicators and economic
forecasting due to the social and political importance of understanding and foreseeing business 2 Additional information about the Stock and Watson Indices is available at http://ksghome.harvard.edu/~.JStock.Academic.Ksg/xri/
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cycles. This subsection highlights articles of particular interest in the area of leading indicators
and their explanatory power.
A starting place for any research into leading economic indicators is the work of James
H. Stock and Mark W. Watson (S&W) as they have focused much of their empirical efforts on
economic indicators. In their 1989 paper, they examine the then current index of leading
economic indictors and propose a new index of their own creation. S&W propose an alternative
index to that of the Department of Commerce (DOC), selecting indicators based on performance
and economic theory. They note that some variables survived their screening process based
solely on their implied importance from economic theory. Using historical data, they compare
the performance of the DOC index to their new index and find that their proposed index offers
substantial improvements over the current DOC index.
The proposed index contains variables not included in the DOC index which offer strong
predictive powers, these being the private-public interest rate spread and the change in the 10-
year Treasury bond yield. Additionally S&W note several indicators included in the DOC index
which “have little marginal predictive content”. These indicators include measure of money
supply, employment, consumption, inventories, investment, and stock market variables. This is a
somewhat surprising conclusion based on the importance of these variables in macroeconomic
theory. Rather than focusing on finding where the predictive power of the then current index
comes from, S&W went about creating their own index which they believe to have more
predictive power than the DOC index. Keeping these conclusions in mind several recent articles
have illustrated the importance of leading indicators in explaining and predicting business cycle
fluctuations.
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In their 1990 essay, Victor Zarnowitz and Phillip Braun (Z&B) examine the role of key
macroeconomic variables and leading indexes in explaining business cycles in three time
periods: Pre-World War I, Interwar, and Post-World War II.3 They use the composite index of
leading indictors due to the fact that several past studies find a “relatively close and stable
relationship between changes in this index and changes in macroeconomic activity.”4 Z&B
justify their inclusion of the leading index for two reasons. First, they state that movements in
the leading index in a broad sense can be seen as a representation of the collective early
outcomes of investment, production, and, to some degree, consumption decisions. Secondly,
including this index in their analysis helps to overcome omitted variable bias as this index
represents a number of significant factors that would otherwise be omitted. Unfortunately, in
their study the index of leading indicators for the prewar period was not found to be significant;
however, Z&B attribute this to data problems and how the index was constructed for this period.
The results of the leading indexes used in the interwar and especially the postwar period were
much more promising. For the postwar period, Z&B find the rate of change in the leading index
to have the most statistically significant effect on the rate of change in real GDP when compared
to other variables used. Overall their study lends support to the importance of the leading index
in explaining GDP fluctuations.
As mentioned above, the original purpose of leading indicators was to predict turning
points in business cycles, rather than to create linear forecast models. James D. Hamilton and
Gabriel Perez-Quiros (1996) (H&PQ) note that anticipating a turning point is conceptually
different from minimizing the mean squared forecast error, and an index of leading indicators
may be useful for one of these tasks but not necessarily the other. H&PQ test to see if the CLI is
3 Indices for the pre and inter war periods were constructed with the best available data. 4 Braun and Zarnowitz (1990) p.357.
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most useful at predicting cyclical turning points or in use in linear forecasting models.
Additionally, they test for and take into account the cointegration between the CLI and GNP,
which arises as a result of how the CLI is constructed. They find the CLI to be a useful tool in
predicting turning points as well as forecasting GNP, and simple linear forecasting to be as good
as their proposed nonlinear models.
In their analysis, they comment on the timeliness of the CLI. The CLI issued one period
is constantly updated in subsequent periods as more accurate data are obtained or when
definitional changes are made. Therefore more accurate values of the CLI for a given month
may come out months later, and this information may no longer be useful for predicting the next
quarter’s GNP. Due to this informational lag, H&PQ warn that the CLI may not be a practical
forecasting tool. Even so, in their real-time exercise they find the CLI to be useful in forecasting
GNP. Additionally, they find the CLI helps in identifying the beginning and end points of a
recession. In testing for cointegration of order one between the CLI and GNP in growth rates,
they strongly reject the null hypothesis of no cointegration, and when accounting for the
cointegration in their previous analysis, their results are only strengthened. Overall H&PQ find
the CLI to be a useful tool in both forecasting GNP and business cycle turning points, and that
these forecasts are best obtained with a simple linear relationship between GNP growth and CLI
growth.
Several recent papers have analyzed the performance of leading indicators in the 2001
recession. Stock and Watson (2003) evaluate the performance of professional forecasts based on
the leading indicators and the predictive power of the individual indicators in this recent
recession. Using data from the Survey of Professional Forecasters, conducted monthly by the
Federal Reserve Bank of Philadelphia, they compare professional forecasts of GDP growth to the
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actual GDP growth figures. Their findings suggest that this was a difficult recession for
professional forecasters to predict. In an attempt to explain why professionals had difficulty
foreseeing this recession, S&W analyze the performance of the individual indicators. To do this,
they run an autoregression which includes GDP growth and a chosen indicator, one
autoregression for each of the leading indicators. They compare the mean squared error of each
autoregression to that of a benchmark GDP growth autoregression. From this, they found
interest rate spreads, stock prices and new claims for unemployment insurance outperformed the
benchmark based on the result that they had lower mean squared errors than the benchmark.
Previously reliable indicators, such as residential building permits and consumer confidence
performed worse than the benchmark.
S&W believe every recession is unique and therefore leading indicators do not perform
consistently from one recession to the next. They note that this conclusion may be disappointing
but not surprising. Since its inception economists realized that recessions differ and suggested
including a variety of indicators in the index for this reason. While there may not be any leading
indicator that proves reliable over time, one hopes at least some of the components will perform
strongly throughout business cycles, so the index as a whole is useful.
Filardo (2004) examined how several recession prediction models preformed in
forecasting the 2001 recession, noting that this is an interesting recession to examine due to its
mildness. He focused on four specific models, traditional rule-of-thumb models, Neftci’s
sequential probability model, a probit model, and Stock and Watson’s experimental recession
indexes, all of which incorporate components of the CLI. Filardo finds that the first three models
are reasonably effective at showing signs of an impending recession, although the basic rule-of-
thumb models which use monthly changes in the CLI give numerous false signals. The Stock
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and Watson experimental recession indexes failed to perform well in this case and Filardo
mentions that they have been criticized for placing too much importance on financial variables
and interest rates instead of traditional CLI variables. This is an interesting result, as S&W had
previously thought their experimental indices to be superior to the CLI. In conclusion, he hopes
that his findings may renew interest in using the CLI indicators in the analysis of business cycle
fluctuations, and additionally that the theory and construction of the CLI will continue to shape
the understanding of business cycles well into the future.
Kevin L. Kliesen (2003) also examines the uniqueness of the 2001 recession and the
performance of various economic indicators and forecasts. He collected data on various
economic series for previous post-war recessions and compares these to the values of the same
series in the 2001 recession. This data comes from Blue Chip Economic Indicators, which
contain data on quarterly forecasts. Kliesen examines forecast errors from a macroeconomic
forecasting model. He concludes that low interest rates helped the economy by allowing interest
sensitive activity, such as new home building and sales, to remain strong, and also that the sharp
declines in business capital spending were due to falling equity prices during the recession.
Dueker (2002) investigates the effectiveness of CLI based forecasts in the 2001 and
1990-91 recessions using various probit models. Forecasting models largely missed predicting
the 1990-91 recession, and Dueker’s study agrees with this common conclusion. Additionally he
finds the 2001 recession to be difficult to predict using the simplest of his three probit models,
which uses percent change in the CLI to predict the probability that the economy will be in a
recession in a specified amount of time. He uses two more models that account for the
probability that the recession occurs in different regimes (in this case low volatility or high
volatility regime). These models did a much better job in predicting an imminent recession,
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which lends support to the belief that changes in the business cycle will affect the predictive
power of CLI components and should be accounted for.
In 2003, Timotej Jagric took a neural network approach5 to construct a new forecasting
model based on leading indicators. The main reason for using neural networks in forecasting is
for questions of functional form, which has been a common theme in forecasting literature.
Jagric looks at the forecasting performance of neural network models since he, along with others,
believes traditional linear models may not adequately describe business cycles. He uses data on
leading indicators for Slovenia for the years 1993 to 2001. While this article does not focus on
U.S. leading indicator data, it lends support to the importance of leading indicators in a larger
context. The neural network model detected all turning points, an important feat that many
forecast models struggle to accomplish successfully. Additionally, this new model overcame
several major deficiencies by correctly forecasting all reference points in in-sample and out-of-
sample data, forecasting future values of the reference series (in contrast to classical leading
indicators models), and the model had a fixed forecast horizon of twelve months.
H.O. Stekler (2003) advises using caution when interpreting movements in the CLI,
noting that many predictions made using the CLI generally miss the turning points. Using
historical data on the CLI to evaluate forecasting performance throughout the past decades, he
finds that forecasts made with real-time versions of the indicators would have failed to provide
any signal of cyclical downturns before they occurred. He questions the ability of the CLI to
actually lead business cycle peaks and troughs. Forecasts using revised historical data however
showed much more promise in predicting turning points; however, this is of little comfort since
often times the revisions are made too late to be used in forecasting. Overall, these disappointing
5 Neural networks are used to determine the best function form. The functional form is selected based on best fit and not necessarily grounded in theory. For additional information see Jagric (2003).
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findings lead Stekler to conclude the CLI might not be as valuable a forecasting tool as some
have believed.
The timeliness of the release of an accurate CLI is a continual concern in the forecasting
literature. A problem with the current procedure for calculating the CLI is that it fails to use the
most up to date information for some components. Indicators included in the CLI can be broadly
classified in two main groups: financial variables and real macroeconomic variables. The real
macroeconomic variables are usually released with a one period lag, as it takes time to compile
the information. On the other hand, financial variables, such as stock prices and interest rate
spreads, are available in real time. McGuckin, Ozyildirim, and Zarnowitz (2001) (MOZ) give
the example of the index of leading indicators that is published in March uses January data,
despite the availability of February data for some of the indicators. They cite this as a possible
cause for the poor performance of the CLI in recent studies. As an alternative, MOZ use the
most up to date information for financial variables and create autoregressive forecasts of the real
macroeconomic variables to bring these variables up to the current period. It is important for all
components in the index to be measures from the same period. Using this alternatively
constructed index, MOZ find that it consistently outperforms the current index for a historical
sample covering the period 1970 to 2000. They feel this new method offers substantial ex-ante
forecasting improvements over the current method.
An additional problem that forecasters may not currently be able to work around is the
inexactness of real macroeconomic indicators and the lag time for their revisions to occur. Due
to this, several economists have proposed indexes which are comprised entirely of financial
variables; however, MOZ warn that performance of financial variables in forecasting varies
across business cycles, and for this reason a more complete index should be used.
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Ruey S. Tsay and Chung-Shu Wu (2003) touch on the timeliness of indicators and
accommodations of the changing environment when forecasting with leading indicators. They
note the economy has undergone numerous advances, especially in computer technology, which
allow for improved data collection and faster informational availability. Due to these structural
changes, which are discussed in the following subsection, Tsay and Wu (T&W) suggest that
frequency of the publication of leading indicator data may be too sparse to effectively capture
movements in the economy; however this is a problem beyond their control. They make use of a
functional-coefficient transfer function model, where the model parameters evolve though the
use of a state variable. This state variable represents changes in economic conditions, and allows
for a changing relationship between the variables as the economy changes state. Using a time
index as the state variable, which they feel proxies for technological development, T&W find
their model outperforms others. As a result of their study, they believe when forecasting with
leading indicators, environmental changes should be taken into account.
These articles lend support to the importance of leading economic indicators in
forecasting business cycles as well as the concerns some have with using them and their
timeliness. It has been shown, however, that if used in the right manner, leading indicators can
yield impressive results in forecasting economic activity.
II. c. Has the Business Cycle Changed and What Effects Does This Have on Leading Indicators?
Problems in the predictive power of leading indicators are perhaps a result of some
fundamental change in the business cycle. While the index is monitored and revised when
necessary, it may be difficult to determine if a perceived change in business cycles is permanent.
As a result of the boom of the 1990s and the quasi-uniqueness of the 2001 recession, many
economists have offered their input as to whether or not there has been a fundamental change in
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the business cycle. Several papers mentioned above concentrated on the inability of professional
CLI based forecasts to predict the 2001 recession.
Victor Zarnowitz, an expert on business cycles, has prepared several recent papers on the
topic of a fundamental change in the business cycle. The long business expansions enjoyed in
the past decades have created expectations of unending economic prosperity; however these
beliefs appear unfounded when taking into account historical information. Zarnowitz (1998)
offers his insight into the belief that business cycles may have been eliminated. In order for
indefinitely long business expansions to occur, he believes real growth must be moderate, prices
of goods and services must rise slowly, and the prices of stocks must be allowed to rise
indefinitely with only minor setbacks. The fact that there have been no deflationary periods
since World War II plays a key role in stabilizing the economy; however there have been periods
of high inflation which has increased uncertainty and hampered economic growth.
Unfortunately, the prices of financial assets appear to be much more volatile, and their
stabilization requires intervention by the Federal Reserve, which has been reluctant to do so.
Zarnowitz warns that too much attention has been placed on single shock causes of cyclical
downturns, such as oil prices in the 1970s and monetary policy shifts in the early 1980s, rather
than overall economic conditions. In past recessions where explanatory emphasis has been
placed on a single shock, these recessions were preceded by declines in overall economic activity
prior to the shock, suggesting there was not a mono-causal source of the recession.
Overall, Zarnowitz states that expansions have become longer, and recessions much
shorter since World War II; key reasons for this being no deflationary periods, a shift of
employment to less cyclical service industries, automatic stabilizers, the creation of the FDIC to
prevent bank failures, and less volatile monetary grow, all of which feed into increased
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consumer, business and investor confidence. However, at best these factors can only limit
business cycle volatility, not eliminate the cycle entirely. Taking this into account, the business
cycle has changed for the better; however, it is not easier to predict. Zarnowitz notes that in
forecasting, economists often miss cyclical turning points, especially the peaks. The concern
arises from what Milton Friedman refers to as the “tyranny of the majority,” where it is in an
individual forecaster’s best interest to go along with the predictions of others. This is an
unfortunate side effect of having a large number of professional forecasters.
Zarnowitz (1999) provides a history of business cycles over the past century, focusing on
what influences them, and comparing trends over time. His motivation is the speculation that the
1990s are the beginning of a new era of economic growth, based on exuberance about economic
stability and innovations in computing technology throughout the decade. He therefore
compares this expansionary period to past expansions in the 1960s and 1980s. Zarnowitz
evaluates the effects of profits, investment, and credit on business cycles. Profits are evaluated
using data from The Conference Boards Business Cycle Indicators for the years 1953 to 1998,
and he uses regression analysis to determine which indicators affect profits and in what manner.
He then does the same for investment and change in investment. This allows him to compare
business cycle conditions over time. Comparing the 1990 expansion to those in the 1960s and
1980s, he notes that overall rise in real GDP and employment was much larger then than in the
1990s. As an additional warning for the United States, Zarnowitz cites examples of growth
turned bad in Asia.
Overall, he concludes that since the 1970s and 1980s, business cycles have become more
moderate, so some of the exuberance is not unfounded. His advice is that people continue to
observe the patterns of endogenous domestic variables that play major roles in foreign business
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cycles, as they are likely to have similar effects in the United States. The occurrence of the 2001
recession and ensuing jobless recovery helped to quell beliefs that business cycles have ended.
While the recession was relatively short and mild, high levels of unemployment have dampened
enthusiasm. Nevertheless, it is important to realize that structural changes and policy
implementations have had a lasting effect on the U.S. economy.
Stock and Watson (2002) also investigate the postulated change in the business cycle, and
find a widespread moderation in volatility in the 1990s as expected. They cite increased stability
of residential investment, the output of durable goods, and the output of structures as the three
most important components in the overall drop in volatility. S&W date the decline in GDP
volatility to the mid-1980s. They find various causes for the increased stability; stating that the
improved monetary policy of the Federal Reserve accounts for 10 to 25 percent of the decline in
output volatility. Additionally, some of the decline can be attributed to less volatile productivity
and commodity price shocks; however much of the decline in volatility is unaccounted for based
on their findings. Previously praised changes, such as the shift from manufacturing to service
and improvements in inventory management, did not seem to provide sufficient explanation for
the decline in GDP volatility. S&W do note a connection between decreased volatility and
increased precision of economic forecasting; however, they cannot account for any specific
source for improved forecasting. Overall, they conclude that the past fifteen years have
exhibited moderate volatility, but much of this seems to be in the form of good luck. The lack of
major economic disturbances may not continue, and S&W feel the U.S. economy could return to
“more turbulent times”.
These papers illustrate that even though the U.S. economy seems to be better off than
ever, it can still plunge into recession. On an encouraging note, it appears structural changes
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since World War II have had a positive effect on the economy as a whole, although there have
been several occasions of economic turmoil since then. Luckily with improved policy and the
lack of major shocks to the economy, economic growth has been able to proceed in a relatively
stable manner. Nevertheless, forecasters and those compiling indexes should keep in mind the
uniqueness of individual business cycles, as well as the overall trends, and not simply use what
has worked best in most recent history.
II. d. Future Research and Motivation
In an area of such great social and political importance, there is clearly room for future
research. Evidence of structural changes to the business cycle, and the recent work of Tsay and
Wu, which examined the role of changes economic environment when forecasting, suggest the
importance of accounting for these economic changes forecasting with leading indicators.
Indeed further research into this area is in order. In general, research into the most effective
methods of using indexes of leading economic indicators to forecast business cycles is merited.
Jaric (2003) was able to obtain impressive results using a neural network forecasting model.
Some economists question the validity of these methods as they lack a basis in economic theory,
however if proven to be effective predictive tools they are sure to be of great benefit. On the
other hand, some forecasters achieved sound results with linear models. Surely the question of
functional form will continue to play an important role in forecasting with leading indicators.
Additionally, work can be done by the Conference Board with the Composite Index of
Leading Indicators, most notably with its timeliness. The research of McGuckin, Ozyildirim and
Zarnowitz (2001) offers a viable method of incorporating the most up to date information in the
creation of the CLI. In light of technological advancements which help to facilitate the
collection of data, one should expect the lag time of many real macroeconomic variables to
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diminish in the near future. Hopefully the Conference Board can make use of advances in
technology in the best possible way to expedite the release of the CLI, although the tradeoff
between timeliness and quality should not be forgotten.
Finally, Zarnowitz and Braun (1990) offer several suggestions for further research, one of
these being of specific interest; they propose trying to determine where the explanatory power of
the CLI comes from. Of the various paths for further research in the area of leading indicators,
this is the on this paper will pursue. Although the importance of using the index as a whole has
been illustrated above, it is a useful exercise to evaluate the performance of individual indicators.
These indicators have been selected for use in the CLI for their ability to precede movements in
the overall economy. In determining the source of predictive power for the index, one can better
understand its ability to predict turning points and forecast values of key macroeconomic
variables and perhaps understand why its ability to predict variations in the business cycle
changes over time.
III. Data
III. a. Selected Variables
Time series data has been obtained for the index of leading economic indicators and
several other key macroeconomic variables. All data are quarterly and span from the first quarter
of 1959 to the first quarter of 2004. Information about the sixteen selected variables is
summarized in Table 1.
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Table 1: Variable Names, Symbols and Sources No. Variable Name Form Symbol Sourcea Notesb
1 Real GDP ∆ln y FREDc Billions of Chained 2000 Dollars, SAAR.
2 GDP Deflator ∆ln p FREDc Index 2000 = 100, SA. 3 Treasury
Constant Maturity ∆ r FREDd Average Of Business Days, in Percent,
Freq. Converted from Monthly. 4 Nominal M2 ∆ln nm2 FREDd Billions US Dollars, Freq. Converted
from Monthly, SA. 5 Federal Current
Expenditures ∆ln g FREDc Billions of US Dollars, SAAR.
6 CLI ∆ln cli DRIe Composite Index Of Leading Indicators, 1996=100, SA.
7 Real M2 ∆ln rm2 DRIe Money Supply, M2, 1996 Dollars, SA.
8 Stock Price Index ∆ln sp DRIe S&P 500 Common Stock Price Index: Composite, 1941-43=10, NSA.
9 Interest Rate Term Spread
level term DRIe 10-Yr Treasury Bonds Less Fed Funds; % Per Annum, NSA.
10 Consumer Expectations
ln level cexp DRIe U of Michigan Index of Consumer Expectations, 1966:2 = 100, NSA.
11 New Housing Starts
ln level house DRIe Housing Authorized: Total New Private Housing Units, in thousands, SAAR.
12 Manufacturing Hours
ln level mfg BLSe Average Weekly Hours of Production, Workers: Manufacturing, SA.
13 New Claims for Unemployment Insurance
∆ln unemp DRIe Average Weekly Initial Claims, State Unemployment Insurance (except Puerto Rico), in Thousands, SA.
14 New Goods Orders
∆ln goods DRIe New Orders (Net) - Consumer Goods & Materials, Billions of 1996 Dollars, SA.
15 New Capital Orders
∆ln cap DRIe New Orders, Non-defense Capital Goods, Billions of 1996 Dollars, SA.
16 Vendor Performance
level vendor DRIe NAPM Vendor Deliveries Index, in Percent, SA.
a. FRED is the Federal Reserve Economic Data (http://research.stlouisfed.org/fred2/), DRI is the Basic Economics Database (2004), published by DRI-WEFA, Inc, BLS is the Bureau of Labor Statistics.
b. SA = Seasonally Adjusted, SAAR = Seasonally Adjusted Annual Rate, NSA = Not Seasonally Adjusted. c. Series maintained by the Bureau of Economic Analysis. d. Series maintained by Board of Governors of the Federal Reserve System. e. Series maintained by The Conference Board.
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Variables one though five in Table 1 account for key macroeconomic variables: output,
price level, interest rate, money supply and government spending, and have been obtained from
the Federal Reserve Bank of St. Louis Economic Data. The remaining variables are the
Composite Index of Leading Indicators (CLI) and its ten individual components. These data are
maintained and published by The Conference Board and have been obtained from the 2004 DRI
Basics database.6 Components included in the CLI have been specifically selected since they
historically turn before business cycles and therefore offer important information about
movements in the aggregate economy. A full description of and justification for the ten
components of the CLI can be obtained from The Conference Board’s official indicators
website.7
III .b. Unit Roots and Variable Transformations:
When working with time series data it is important to check for the presence of unit roots
before proceeding to statistical modeling. Neglecting to account for non-stationary variables can
result in biases caused by spurious correlation between the variables. The Augmented Dickey-
Fuller (ADF) procedure is used to test for the presence of unit roots. The Dickey-Fuller test is
only appropriate for first order autoregressive processes, whereas the ADF Test can handle
higher order correlation due to the presence of lagged first difference terms. The test is
conducted by performing the following regression:
(1) t
N
nntit ytayay εβγ +∆+++=∆ ∑
=−−
1210
where y is the specific time series variable in question, a0 is the constant term, t is the time trend,
and N = 4 quarterly lags. The null hypothesis is:
6 Data for average weekly manufacturing hours, could not be obtained from the 2004 DRI Basics database, and was therefore obtained directly from the Bureau of Labor Statistics. 7 http://www.tcb-indicators.org/GeneralInfo/component_description.cfm
MA Exit Paper Delehunt 20
0:0 =γH (2)
where failure to reject represents the presence of a unit root. The ADF Test statistic is a t-
statistic calculated by dividing the coefficient γ, by its standard error.8 This test is conducted for
each of the sixteen variables in Table 1. Test statistics are computed using Equation (1) with a
trend and constant terms (stationary around a trend) and with the coefficient on the time trend, a2
restricted to zero (mean stationary). These results are summarized in Table 2 below. ADF Test
statistics are listed for tests with a time trend and constant (ττ) and with a constant term only (τµ).
Table 2: Unit Root Test Statisticsa
I. Tests on Levelsc II. Tests on First Differencesc
Seriesb ττ τµ ττ τµy -2.89713 -0.84658 -5.67476* -5.58784* p -1.87996 d -1.59285d -2.23539 d -2.0276 d
r -1.76641 -1.82332 -5.33868* -5.23661* nm2 -0.73617 -2.04157 -3.49764+ -3.04664+
g -0.24383 -2.28579 -4.73395* -4.08576* cli -3.68138+ -1.44088 -6.02582* -5.98319* rm2 -2.97809 -1.60449 -4.00331+ -3.89312* sp -1.75422 0.131102 -5.9349* -5.89323* term -4.18999* -3.95674* -5.57132* -5.5801* cexp -2.90159 -2.9611+ -6.28165* -6.2732* house -3.66025+ -3.47394+ -5.44139* -5.46639* mfg -3.23397° -2.8939+ -6.39628* -6.41573* unemp -2.74393 -2.52149 -6.26745* -6.28615* goods -2.99081 -1.8993 -5.89226* -5.76336* cap -3.3486° -1.96558 -6.18339* -6.12914* vendor -4.9819* -4.87057* -7.29915* -7.32027*
a. ττ is the ADF test statistic for tests including a constant plus time trend, τµ is the ADF test statistic for tests with a constant but no time trend.
b. For variable definitions see Table 1. All variables are in natural logs except r, term, and vendor. c. Significance at the 1% level is represented by *, at the 5% level by +, and at the 10% level by °. d. While the price level, p is not stationary in either levels or first differences under the ADF Test, it is
stationary according to the Phillips-Perron Test (with constant and without trend) in first difference form with a test statistic of -3.00116, which is significant at the 5% level.
8 Critical Values are tabulated in Enders (2004) Table A, p. 439, reproduced from Fuller, W. A. 1976. Introduction to statistical time series. New York: Wiley.
MA Exit Paper Delehunt 21
While variables such as term, cexp, house, mfg, and vendor are all stationary in levels, in
some cases transformations were necessary to create stationary variables. Part II of Table 2
shows that almost all series are stationary using the ADF test on first differences. Therefore y, r,
nm2, g, cli, rm2, sp, goods, and cap have all been first differenced for use in further statistical
analysis. Normally price levels are stationary in either levels or first differences; however the
price level chosen in this analysis, the GDP implicit price deflator, is not stationary in either form
over the selected range when using the ADF test. While not stationary under this traditional test,
the series is stationary in first difference form when using the Philips-Perron Test for unit roots at
the 95 percent confidence level. The Phillips-Perron Test has been deemed acceptable for the
purposes of this study and the first difference of the price level is used in the subsequent analysis.
Additionally, unemp is nearly stationary at the 10 percent level. This variable is “on the fence”
between being stationary in levels and being stationary in first differences. In the ensuing
analysis, the form used has no considerable effect on the results; however, the ADF Test
indicates the first difference form should be used and therefore these are the results reported in
Section V.
IV. Model
A standard vector autoregression (VAR) composed of output, inflation, money supply,
interest rate, and government spending, is used as the baseline statistical model. The model is in
the form of equation (3) below:
(3) t
J
jitjij
I
it exx ++= ∑∑
=−
= 1,
10 αα
where xt is a ( vector containing variables one through five listed in Table 1 above, α)
)
15× t is a
vector of intercept terms, I = 4 quarterly lags, J = 5 endogenous variables, and e( 15× t is a
MA Exit Paper Delehunt 22
( 15× ) vector of error terms. A time trend was initially included in Equation (3) as well, however
in many cases it was not statistically significant and its presence had no significant impact on the
results. Due to these factors, it has been omitted and all results reported are for specifications
without a time trend.
In order to test the explanatory power of the individual components in the CLI, four
quarterly lagged values of the CLI or one of its individual components were added to
Equation (3) above, resulting in the following transformation:
(4) ( ) t
J
jtjijitjij
I
it eCLIxx +++= ∑∑
=−−
= 11,,
10 βαα
where CLI represents either the composite index of leading indicators as a whole or one of its
individual components. Given that there are ten components and the overall index, eleven
variations of Equation (4) are estimated using ordinary least squares.
Using a specification like Equation (4) helps to eliminate biases caused by omitted
variables. For each dependent variable, xt, predictive power from its own lagged values and
from the other key macroeconomic variables is controlled for. Therefore when a particular
component is added, this component is not picking up the effect of other macroeconomic
variables. In explaining output, for example, the predictive power of its lagged values, as well as
that of lagged values of the price level, interest rate, nominal money supply and government
spending are accounted for. When a CLI component is added and found to offer predictive
power of output, this predictive power can more accurately be attributed to the component itself,
rather than other key macroeconomic variables.
While the first part of this analysis looks at the overall predictive power of CLI
components, the second part examines the marginal predictive power of the components. This
can help to give an idea of whether or not some components offer more predictive power than
MA Exit Paper Delehunt 23
others. For this analysis a transformation of Equation (3) is used which includes all of the CLI
components in the regression, rather than just one at a time as in Equation (4).9
(5) ( ) t
J
jtjijtjijitjij
I
it eCLICLIxx +++++= ∑∑
=−−−
= 11,101,1,
10 ... ββαα
Equation (4) tests for the overall predictive power of an individual component, whereas Equation
(5) examines the question in a different way: given the regression includes nine of the CLI
components, when the tenth is added, is there any additional predictive power? Looking at
marginal predictive power examines the question, does this component really belong in (i.e. add
to) the CLI?
The test for explanatory power, either overall or marginal, from an individual component
is an F-statistic which tests the null hypothesis:
0...: 410 === −− tt CLICLIH (
6)
against the alternative hypothesis that the coefficients on all lagged values of a component are
not equal to zero. In order for a component to have predictive power over the selected dependent
variable, at least one of the four lagged values must be statistically different from zero. In
checking for overall predictive power, this test is conducted for the index and all ten components
for each of the five dependent variables. The test to see if a component adds predictive power,
after the other nine components have been accounted for is performed ten times, once for each of
the individual components. Results for both analyses are reported in the following section.
9 The CLI itself is not included in the second analysis, as it would then pick up some of the effects of the individually tested component.
MA Exit Paper Delehunt 24
V. Results
V .a. Overall Predictive Power
The values of the coefficients from the individual regressions are of little interest in this
study, and as a result are not reported. What is relevant is the joint significance of the four
lagged values of each individual component, as this illustrates its predictive power on the
selected dependent variable. Table 3 lists the results of the joint hypothesis test on the four
lagged values of the CLI and its components for each of the five dependent variables. A “yes”
indicates that the selected component adds predictive power to the specified dependent variable,
i.e. a rejection of the null hypothesis. The statistical significance of a “yes” is denoted by it
superscripted symbol. A “no” indicates failure to reject the null hypothesis and therefore no
added predictive power from the selected component on the specified dependent variable.
Of particular interest is the explanatory power of an individual component on y, as it is a
measure of overall economic activity, and the index was designed to predict economic turning
points. It is surprising to see that nearly every component in the CLI offers statistically
significant explanatory power to real GDP. Based on previous research, one might have
expected a few of the components to have strong predictive power of output, but probably not
expect to see nearly every component being accountable for the predictive power of the leading
index. Due to the manner in which the idea is proposed in Zarnowitz and Braun (1990), it seems
the authors would expect the predictive power of the index to be derived from a few key
components.
In addition to predicting levels of and changes in output, the CLI may offer explanatory
power to other important macroeconomic variables, such as price level, interest rates, money
MA Exit Paper Delehunt 25
vend
or
yes°
yes*
no
no
yes+
cap
yes+
yes*
no
no
no
good
s
yes°
no
no
no
no
unem
p
yes*
yes°
no
no
no
mfg
no
no
no
no
no
hous
e
yes*
yes*
no
no
no
cexp
yes+
no
yes°
no
no
term
yes+
yes+
no
yes+
no
sp
yes*
no
yes+
no
no
rm2
no
yes*
no
no
no
CLI
Com
pone
ntb,
c,d
cli
yes*
no
yes*
no
no
a.
See
Tabl
e 1
for v
aria
ble
defin
ition
s. b.
Ea
ch c
olum
n re
pres
ents
the
spec
ifica
tion
show
n in
Equ
atio
n (3
) plu
s the
CLI
com
pone
nt d
enot
ed b
y th
e co
lum
n he
adin
g.
c.
H0 :
CLI
t-1 =
… =
CLI
t-4 =
0
Yes
: Rej
ectio
n of
the
null
hypo
thes
is, a
t lea
st o
ne la
gged
val
ue o
ffer
s pre
dict
ive
pow
er.
N
o: F
ailu
re to
reje
ct th
e nu
ll hy
poth
esis
.
d.
Sign
ifica
nce
at th
e 1%
leve
l is r
epre
sent
ed b
y * , a
t the
5%
leve
l by
+ , and
at t
he 1
0% le
vel b
y °.
Tab
le 3
: D
oes t
he S
elec
ted
Com
pone
nt O
ffer
Ove
rall
Exp
lana
tory
Pow
er?a
Dep
Var
iabl
e
y p r
nm2 g
MA Exit Paper Delehunt 26
supply and perhaps even government spending. The results of the predictive power of the CLI
on these other macroeconomic variables are summarized in rows two through five of Table 3.
Many of the components have statistically significant predictive power on the price level,
p; however, the index as a whole does not. While one can expect a relationship between price
level and money supply, many of the other components may predict p, because they predict
nominal GDP. Nominal GDP is p times y, therefore components that affect y also have an effect
on p. This is the hypothesized reason behind the high number of components that have
statistically significant predictive power of the price level. While many components are
significant, the reason the index itself has no statistically significant predictive power may be
that the CLI is not composed in a manner to best predict price level.
The Treasury Constant Maturity Rate, r, is the only other key macroeconomic variable in
this study besides output which receives significant explanatory power from the CLI; however,
many of the individual components are not statistically significant. The explanatory power of
the CLI on interest rates is therefore derived from only one or a few individual components. The
most highly significant component in explaining interest rates is the S&P 500 index of common
stock prices, sp. Movements in this index reflect movements in interest rates due to the ceteris
paribus inverse relationship between interest rates and stock prices. Interest rates can be viewed
as the opportunity cost of holding stocks, and therefore stock prices can offer some predictive
power as to the movement of interest rates. The other component, significant as the 10 percent
level, is the index of consumer expectations, cexp. Consumer expectations can be heavily
influenced by interest rates. Higher expectations can be representative of lower interest rates, as
consumers are able to finance the purchase of durables under desirable terms. It is interesting
MA Exit Paper Delehunt 27
that the CLI has such statistically significant predictive power of interest rates, yet only two of
the components are statistically significant.
Only term has significant predictive power of Nominal M2 Money Supply. This should
not be surprising as the Federal Reserve controls the money supply and enacts a policy of interest
rate targeting. The spread can indicate inflation expectations as the 10-year Treasury bond rate
has inflation expectations built into it. As the spread widens it represents an increase in expected
future inflation which is related to money supply. Also, the Federal Reserve targets the federal
funds rate using monetary policy, so one should expect a close relationship between money
supply and the federal funds rate. The discount rate is closely related to the federal funds rate,
and therefore offers predictive power of nominal M2. The Conference Board itself says this
particular indicator is felt to be an indicator of the stance of monetary policy because it rises
when short term rates are low and falls when short term rates are high.10 Based on this, one
would expect to find this indicator to have some predictive power of the nominal money supply.
The CLI and its components have almost no predictive power of government spending.
This should not be surprising however, since often times government spending decisions are
made either independently of or opposite to macroeconomic activity. One might expect interest
rates to have some small influence on government spending; however, in this study it offers no
statistically significant predictive power. The only component to have any significant
explanatory power of government spending is vendor performance. As stated by The
Conference Board, “this index measures the relative speed at which industrial companies receive
deliveries from their suppliers.”11 Government purchases lead to an increase in demand for
manufacturing supplies, which in turn can lead to slower delivery of supplies if this increase
10 http://www.tcb-indicators.org/GeneralInfo/component_description.cfm 11 Ibid.
MA Exit Paper Delehunt 28
demand is not entirely foreseen. Additionally, at times when vendor performance is already
slowed, government purchases may be postponed. Therefore it is possible to imagine cases
where vendor performance can have predictive power over government spending. Overall it is
no shock that only one variable offers statistically significant explanatory power to federal
government spending, as federal purchasing decisions are generally not constrained by
macroeconomic conditions.
Also of notable interest is that average weekly manufacturing hours offers no statistically
significant explanatory power to any of the five dependent variables included in this study. One
would expect that a component included in the CLI would offer predictive power of at least one
of the key macroeconomic variables included in this study. Perhaps it is simply included due to
its theoretical significance.
V. b. Marginal Predictive Power
The test results for the marginal predictive power analysis are summarized in Table 4,
which is formatted similar to Table 3. As may be expected some components, which offered
overall predictive power do not offer statistically significant marginal predictive power and no
components which failed to offer overall predictive power were able to offer marginal predictive
power. Changes in predictive power from the overall test to the marginal test are indicated by a
superscripted delta. Again of key interest is the predictive power of CLI components with
respect to output, as the index was created to predict overall economic activity. From the eight
components which offered statistically significant predictive power in the overall analysis, only
four remain after the marginal analysis. These components can be seen as having more
predictive power than others, as they have passed this second round of screening. Two of those
surviving indicators are financial variables, stock prices and the interest rate spread, which have
MA Exit Paper Delehunt 29
vend
or
yes°
yes*
no
no
no∆
cap
no∆
no∆
no
no
no
good
s
no∆
no
no
no
no
unem
p
no∆
no∆
no
no
no
mfg
no
no
no
no
no
hous
e
yes+
yes*
no
no
no
cexp
no∆
no
no∆
no
no
term
yes*
no∆
no
yes*
no
sp
yes+
no
no∆
no
no
CLI
Com
pone
ntb,
c,d
rm2
no
yes*
no
no
no
a.
See
Tabl
e 1
for v
aria
ble
defin
ition
s. b.
Ea
ch c
olum
n re
pres
ents
the
spec
ifica
tion
show
n in
Equ
atio
n (3
) plu
s all
10 C
LI c
ompo
nent
s. T
he
hypo
thes
is te
st is
for 4
lagg
ed q
uarte
rly v
alue
s of t
he c
ompo
nent
den
oted
by
the
colu
mn
head
ing.
c.
H
0 : C
LIt-1
= …
= C
LI t-4
= 0
Y
es: R
ejec
tion
of th
e nu
ll hy
poth
esis
. N
o: F
ailu
re to
reje
ct th
e nu
ll hy
poth
esis
. °
d.
Sign
ifica
nce
at th
e 1%
leve
l is r
epre
sent
ed b
y * , a
t the
5%
leve
l by
+ , and
at t
he 1
0% le
vel b
y ° .
A
chan
ge in
pre
dict
ive
pow
er fr
om th
e ov
eral
l to
the
mar
gina
l tes
t is r
epre
sent
ed b
y ∆ .
.
Tab
le 4
: D
oes t
he S
elec
ted
Com
pone
nt O
ffer
Any
Mar
gina
l Pre
dict
ive
Pow
er?a
Dep
Var
iabl
e
y p r
nm2 g
MA Exit Paper Delehunt 30
both been successful predictors in previous research. The other two are new housing starts,
which failed to perform successfully in recent history and vendor performance, Chairman
Greenspan’s indicator of choice.
As for the other macroeconomic variables included, there is a similar trend of fewer
components having statistically significant marginal predictive power than in the overall
analysis. Real M2 money supply still offers predictive power to the price level; however, several
of the other components that previously had statically significant predictive power no longer do.
There are no changes in the predictive power of the components with respect to nominal M2. On
the other hand, no components offer any statistically significant marginal predictive power to
either the treasury interest rate or government expenditures.
VI. Conclusion
These results show that nearly all components included in the CLI offer predictive power
to real GDP when evaluated on their own; however when the other CLI indicators are accounted
for the number of indicators still exhibiting predictive power diminishes by half. All but the real
M2 money supply component and the average weekly manufacturing hours components are
statistically significant in explaining real GDP in the overall analysis. The presence of these
indicators in the CLI that failed to provide any overall predictive power should likely be
reevaluated. Additionally previous research has not showcased either real M2 money supply or
average weekly manufacturing hours as particularly strong indicators. Those indicators which
additionally demonstrated marginal predictive power most likely deserve their place in the index
of leading indicators. These variables, especially the financial ones, have performed well over
time and previous research has praised their predictive power.
MA Exit Paper Delehunt 31
The results for the predictive power of the CLI and its components for the other key
macroeconomic variables included in this study are less powerful, especially when one considers
the marginal predictive power results. While this may be less than desirable, the intention of
these leading indicators is to predict movements in the aggregate economy and therefore their
predictive power of other variables may be lacking. These indicators should not be the ones of
choice if the goal is to predict future levels of other key macroeconomic variables.
While this study does find significant overall explanatory power of real GDP from nearly
every component in the index over the past 40 years, revised, up to date data has been used, a
luxury forecasters do not have. Many of the papers highlighted in Section II that questioned the
power of the leading index have used unrevised data. The contradiction in results adds support
to the need for more timely data for the index to be used as an accurate predictive tool. The main
conclusion from Steckler (2003) was that revised data offered substantial improvements to the
CLI, however without this he seriously questioned the index’s worth. Additionally, McGuckin,
Ozyildirim, and Zarnowitz (2001) offer a compelling approach to improve the timeliness of data;
one which deserves the attention of those in the business of compiling such indices. As this
study has shown that many components of the CLI offer statistically significant overall
predictive power of output and half of these also provide significant marginal predictive power,
the CLI should continue to be used as a valuable predictive tool.
MA Exit Paper Delehunt 32
References:
Enders, Walter (2004), Applied Econometrics Time Series, Hoboken: Wiley. Dueker Michael J. (2002), “Regime-Dependent Recession Forecasts and the 2001 Recession,”
Review, Federal Reserve Bank of St. Louis, November/December. Filardo, Andrew J. (2004) “The 2001 U.S. Recession: What Did Recession Prediction Models
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The Journal of Business, 69(1). Jagric, Timotej (2003), “Forecasting with Leading Economic Indicators – A Neural Network
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Stock, James H. and Mark W. Watson (2002), “Has the Business Cycle Changed and Why?”
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Tsay, Ruey S. and Chung-Shu Wu (2003), “Forecasting with Leading Indicators Revisited,”
Journal of Forecasting, 22.
MA Exit Paper Delehunt 33
Zarnowitz, Victor (1992), “Business Cycles: Theory, History, Indicators, and Forecasting,” NBER Studies in Business Cycles, Volume 27. Chicago: University of Chicago Press, 357-381. [Reprinted from Zarnowitz and Braun 1990]
Zarnowitz, Victor (1998), “Has the Business Cycle Been Abolished?” NBER Working Paper
No. 6367. Zarnowitz, Victor (1999), “Theory and History Behind Business Cycles: Are the 1990s the
Onset of a Golden Age?” Journal of Economic Perspectives, 12(2).