The Human Population:The Human Population:Patterns, Processes, and ProblematicsPatterns, Processes, and Problematics

Lecture #3: Demographic DataLecture #3: Demographic Data

Paul SuttonPaul Sutton

psutton@du.edupsutton@du.edu

Department of GeographyDepartment of Geography

University of DenverUniversity of Denver

Chapter 2: Demographic Data

• GIS data for Denver Metro Area:

• States, Counties, Tracts, Block Groups, and Blocks….

Census of the Population

• United Nations definition:

“The total process of collecting, compiling, and The total process of collecting, compiling, and publishing demographic, economic and social publishing demographic, economic and social data pertaining, at a specified time or times, to data pertaining, at a specified time or times, to all persons in a country or delimited territoryall persons in a country or delimited territory”

• Vital Statistics (Births and Deaths)

• Population Registers

• Sample Surveys

• Historical Sources (church records of baptisms etc.)

Motivation for a Census of the Population(Why were/are censuses conducted?)

Historically (Taxation, Military, Political)Who and where are my taxpayers?

How many soldiers can I conscript?

How many laborers will build a pyramid in my honor?

Today (Scientific, Economic, & Political)How many congressmen should Wyoming have?

Where should federal highway funds go?

Where is the West Nile Virus most dangerous and possible?

Historical censuses

• Egypt, Babylon, China, India, & Rome

• Rome conducted a census of Roman citizens for hundreds of years, extended this to Roman subjects in 5 b.c.

• Mohammed conducted a city-state census of Medina in the 7th century

• William of Normandy’s “Domesday Book” was created to enumerate people, land, and wealth of Norman Conquest in 1089

• The Castato in Florence Italy (1427-1429)

The Domesday BookDomesday has been called one of the three most

famous books in the world, alongside the Bible and the Koran, and is acknowledged as being one of the most important historical documents of the first millennium. William the Conqueror’s great survey has been used as a working document ever since its commission at Christmas 1085, and remained pre-eminent as a census of England until the 19th Century. It was last consulted for legal precedent in 1982, 896 years after it was written.

Maps

Census and Property Survey for Florentine Domains and the City of Verona in Fifteenth Century Italy, also known as

the Catasto study.

The Domesday Book And the Castato Study Are two pre-Nation State Censuses of the population. The Castato study more detailed Than Domesday because it counted All people not merely “Hearths”

Statistic: ‘Facts about a State’

• Sweden in 1749 conducted regular census

• Denmark & Some Italian states late 18th century

• England’s first census 1801

• First United States census 1790

• Taking a census has evolved from counting people (adult men in the very beginning) to measuring literacy, race, income, employment, commuting distances, etc.

Public reaction to national census• Germany’s census in 1983 postponed to 1987 due

to concerns about privacy violation. No census in Germany since then.

• Protests in England, Switzerland, and the Netherlands since then.

• Censuses are infrequent and often inadequate in less developed countries despite U.N. encouragement for conducting censuses.

• U.S. census required by the Constitution

"Representation and direct Taxes shall be apportioned among the several States which may be "Representation and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers ... . The actual Enumeration included within this Union, according to their respective Numbers ... . The actual Enumeration shall be made within three Years after the first Meeting of the Congress of the United States, shall be made within three Years after the first Meeting of the Congress of the United States, and within every subsequent Term of ten Years, in such Manner as they shall by Law direct." and within every subsequent Term of ten Years, in such Manner as they shall by Law direct."

-- -- Article I, Section 2 of the Constitution of the United States Article I, Section 2 of the Constitution of the United States

Has the whole world’s population ever been enumerated at one time?

• From 1953-1964 ~78 % of total counted

• From 1965-1974 ~55 % of total counted*

• From 1975-1984 ~96 % of total counted

• From 1985-1994 ~90 % of total counted

• From 1995-2004 ~91 % of total counted**

• *China excluded ** Projected

Some Big Censuses• China’s Census 2000 had over 10 million enumerators

to count over a Billion people (1.26 Billion)• Year 2000 Chinese population 12% greater than 1990• India’s Census 2000 used only 2.2 million

enumerators to count 1.027 Billion people• 21% Growth over 10 years

What was resultOf U.S. Census

2000?

How well did weCount ourselves?

How often are censuses taken?

• United States has conducted a census every 10 years since 1790

• India has a record of taking a high quality census every ten years since 1881

• Generally, most nations conduct a census every ten years.

• Nigeria (world’s 10th most populous state) has had some problems

Nigerian Census StoryNigeria’s population is divided among 3 broad

ethnic groups: the Hausa-Fulani in the north, who are predominately Muslim; the Yorubas in the Southwest (of various religious faiths) ; and the largely Christian Ibos in the Southeast. 1952 census indicated the Hausa-Fulani had largest share of population. Hausa-Fulani consequently dominated first post-colonial government in 1960. New census in 1962 showed Hausa-Fulani only 30% of population. A “recount” in 1963 changed the Hausa-Fulani proportion from 30% to 67%. Ethnic tensions flared. Ibos declared independence. Result: Biafran War (1967-70) with 3 million dead. Ibos rejoined Nigeria. A census in 1973 never accepted by government. A 1991 census (promising no questions about religion etc.) counted 88 million (much less than expert opinion placed at 110 million).

Nigeria today has ~126 million

The United States Census• Even in 1790 we found out more than just how

many people there were: (1790: # Free white males over 16, Free white females, slaves, & other persons)

• Census questions are reflections of social importance of various categories.– Foreign born population (migration)– Employment, mental health status, race

Census questions are added and deleted by Census bureau via consultation with congress

U.S. Census continued…• Early U.S. census conducted by U.S. Marshals• 1880 special census agents (enumerators) hired• 1902 U.S. Census Bureau created as official government

agency within Dept of Commerce• Census 2000 had the new ‘Multi-Racial’ option• Hispanic/Latino/Spanish still a cultural rather than a

race or ethnicity question• From 1790 to 1930 all people asked all questions• Since then a short form for most (5 of 6) with Long

form for a smaller sample of the population.

Everything you ever wanted to know about Census 2000 but were afraid to ask

• Cost: 6.7 Billion Dollars ($24 per person counted)

• Privacy: Yes…..but not after 72 years• Temp Labor Force: 860,000 (~1 in 325 Americans)

• Response Rates*: 1990 – 65% 2000 – 67% * the universe of households that had responded to the census and would not need a personal visit by an enumerator

• Too many Questions? Short form only 7 questions shortest form since 1820

• Congress and Senate represent those counted in Census, not just voters

• Final Tally: 281,421,906 13.2 % increase since 1990• How many significant figures do you think are in the above number?

Some interesting Census stats on Colorado

• Population Colorado 1990: 3,294,394• Population Colorado 2000: 4,301,261• 31 % Growth over decade (3rd fastest state)• Colorado gained a 7th congressional seat• More skier visits (11 million) than population• More chickens (4.47 million) than people• Cattle are close (3.1 million)• Vehicle/person ratio almost 1 (4,130,345

vehicles)

Who is included in the Census?(I.e. who gets counted?)

The de facto population – Who is in that space on a given day.The de jure population – Those who ‘legally belong’ to a particular place (admin boundary) on a given day

Countries like Mexico with many of their citizens working Temporarily in the U.S. have larger de jure than de facto populations

Countries in the Middle East like Saudi Arabia have high numbersOf ‘guest workers’ from other countries and consequently have Higher de facto than de jure populations

The U.S. Census ‘Usual Residence’ rule

• Most countries including the U.S. compromise between de facto and de jure and use a concept called ‘Usual Residence’. (where a person usually sleeps)

– College students where college is located– Homeless people where they are found– Visitors and tourists not counted– Illegal aliens (‘undocumented’) are counted

• North Carolina vs. Utah Census 2000– Overseas military vs. Overseas missionaries– North Carolina won and got the extra seat in Congress

Types of Error in a Census Enumeration

• Non-Sampling Error– Coverage Error (combo of undercount & overcount)

• Overcount (people counted at two places e.g. ‘snowbirds’)

• Undercount (homeless, illegal immigrants, etc. not counted)• Differential Undercount (Blacks undercounted more than whites)

– Content Error (poorly designed survey instrument)• Confusing questions (multi-race maybe, problems w/ coding)

• Sampling Error– Long Form only goes to 1 in 6

• some error extrapolating, also, larger non-response bias

How are Errors measured?

• Undercount in Census 2000 estimated at 1.2%• 1940 Census measured % Black & % White• 229,000 more Blacks than expected signed up

for the Draft in WWII. This exposed PROBLEM• Demographic Analysis (DA)

Pop(t2) = Pop(t2) + Births – Deaths + immigration – emigration

Problem (how good is Birth, Death, & migration data?)

• Dual System Estimation (DSE)Intensive second survey of selected areas compared to recent censusAlso other records such as DMV driver’s license records can be proxies

Continuous MeasurementThe American Community Survey

• The decadal nature of the census is fairly coarse temporal resolution of demographic change

• The American Community Survey (ACS) started in 1996 will survey approximately 250,000 households per month

• Finer temporal resolution traded for spatial resolution

• Will eliminate the long form from 2010 census

The Census of Canada• Louis XIV decreed a census of the French colony

of New France in 1666 (pop 3,215)

• France ceded Canada to British in 1763, British conducted fairly regular censuses

• Provinces of Canada united in 1867, censuses required for allocation of reps to House of Commons

• Census Bureau of Canada known as ‘Statistics Canada’ (census done quinquennially every 5 years)

• Language (French & English) a big issue there

The Census of Canada continued..

• Housewife in Saskatoon refused to fill out 1991 form because it did not recognize her unpaid housework and child care (changed 1996 form)

• Canada (and U.S.) no longer ask women how many children they have given birth to.

• Canada uses a ‘Reverse Record Check’ and an ‘Overcoverage study’ to estimate errors.

• Canada’s 1991 census was 2.9% undercounted

The Census of Mexico• Spain conducted census in 1790• Mexico gained independence in 1821• First modern census of Mexico in 1895• Censuses done every 10 years in Mexico• Instituto Nacional de Estadistica Geografica y Informatica

(INEGI) is Mexican Census Bureau• Mexico interested in # of international migrants not present

or out of country in last 5 years• Most Mexicans are ‘mestizo’ or mixed race so race/ethnicity

identification not as important• Income not accurately measured• Some interest in Native American Languages• 1990 undercount estimated to be between 2.3 and 7.3 percent

Vital Statistics• Births, Deaths, Abortions, Marriages, & Divorces are all

demographic events of sufficient significance to be recorded by governments

• Originally began as a chore of the Church. (e.g. recording burials, baptisms, marriages, etc.)

• Vital statistics very useful when used in combination with Census data

• Population Registers record these events (used in place of census in the Netherlands)

• In General, the more economically developed the country the better the recording of vital stats, census data, and population register (PR). (PRs also include change of residence)

• Population Register eschewed by U.S. because people fear it is too invasive and powerful a database.

John Graunt: “Father of Demography”• Haberdasher who used his spare

time to determine that for every 100 people born in London only 16 were still alive at age 36 and only 3 at 66. His analysis of vital statistics the beginning of demography, life tables, actual tables, calculation of life expectancy, social, economic, and geographic influence on life expectancy, fertility etc. His observations of the ‘Bills of Mortality’ laid ground for the creation of institutions such as the Bureau of Vital Statistics.

Examples of Combining Census and Vital Statistics

• In 1999 in the U.S. vital statistics showed that there were 3,959417 births. Without Census data you could not calculate a birth rate of 3,959,417/272,691,000 = 14.5 births/1000 people

• This birth rate was lower than in the 1990 value of 16.7

• Intercensal estimates of total population can be made by using vital statistics (births & deaths) plus estimates of emigration and immigration

• Estimate of U.S. pop in 2000 by this means was: 274,520,000 Census measured: 281,421,906

• Difference probably due to bad information about illegal immigration

Administrative Recordsprovide many proxy clues to population dynamics

• Immigration & Naturalization Service (INS)

• Social Security Administration

• Phone Company Records

• Gas & Electric Company Records

• Dept of Motor Vehicles Records

• Internal Revenue Service (IRS) records

• School enrollment Data

Sample Surveys• Carefully designed and executed surveys of relatively

small populations can provide very good information about the population they were sampled from

• Sample surveys often gather social, psychological, economic, and even physical information in addition to standard demographic information

• American Community Survey (ACS), Current Population Survey (CPS), Survey on Income and Program Participation (SIPP), American Housing Survey (AHS), National Center for Health Statistics (NCHS), National Survey of Family Growth (NSFG), National Health Interview Survey (NHIS), others similar surveys in Canada and Mexico

• Other Surveys: Gallup, Political, Academic, Commercial

Historical Sources of Demographic Information

• Archaeological Demography• Church Records• Graveyards• Family Geneologies• Some Lessons learned

– Conjugal Family not a product of industrial revolution

– Extended Family in U.S. prior to 20th century more prevalent than previously thought

• Guns, Germs, and Steel has much to say on this

Census Data and Geographic Information Systems (GIS)

Summary• Demographic Data comes from censuses, population

registers, vital statistics, surveys, Administrative records, and Historical info

• Demographic data used in a GIS had great utility for understanding many political, social, economic, and environmental phenomena

• Next Up: Theories about Demographic Change and Response

• Discussion Question: Texbook Essay– To adjust or not to adjust – That was the question; or was it much ado about nothing.What was the flap about sampling and the census 2000?