The Human Population:
Patterns, Processes, and Problematics
Lecture #3: Demographic Data
Paul Sutton
Department of Geography
University of Denver
Chapter 2: Demographic Data
• GIS data for
Denver Metro
• States,
Tracts, Block
Groups, and
Census of the Population
• United Nations definition:
“The total process of collecting, compiling, and
publishing demographic, economic and social
data pertaining, at a specified time or times, to
all 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 Book
Domesday 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being one of the most important historical
documents of the first millennium.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
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
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,
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
Has the whole world’s population
ever been enumerated at one time?
From 1953-1964
From 1965-1974
From 1975-1984
From 1985-1994
From 1995-2004
• *China excluded
~78 % of total counted
~55 % of total counted*
~96 % of total counted
~90 % of total counted
~91 % of total counted**
** 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 result
Of U.S. Census
How well did we
Count 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 Story
Nigeria’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 HausaFulani had largest share of population. HausaFulani consequently dominated first postcolonial 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 numbers
Of ‘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 census
Also other records such as DMV driver’s license records can be proxies
Continuous Measurement
The American Community Survey
• The decadal nature of the census is fairly
coarse temporal resolution of demographic
• The American Community Survey (ACS)
started in 1996 will survey approximately
250,000 households per month
• Finer temporal resolution traded for spatial
• 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
Administrative Records
provide 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
Family Geneologies
Some Lessons learned
– Conjugal Family not a product of industrial
– 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)
• 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?

An Overview of Methods for Estimating Urban Populations