Dudley L' Poston, Jr'

1
Dudley L. Poston, Jr. Age and Sex
Composition TEDA Meeting (Houston
chapter), June 19, 2008
2
Demography is Destiny

• The phrase is attributed to the 19th century
  French mathematician and philosopher, August
  Comte (17981857), who is known as the father of
  sociology.

3
August Comte (1798-1857)?
4
What does the phrase mean?

• The social, cultural and economic fabric of a
  nation derives in large part from its demography.
  
• For instance, many hold that a country's crime
  rate results from a complex mix of social
  factors, and it does. But the rate is traced
  mainly to a single demographic statistic the
  number of young men between 15 and 30 years of
  age this is the population cohort responsible
  for the most crime.

5
The demographic data that are a populations
destiny

• AGE SEX
• Importance, definition and measurement?

6
Age and Sex Structure and Its Importance The
age and sex structure of a population is simply
the distribution of the population by age and
sex. Of all the characteristics of human
populations, age and sex are the most important
and relevant owing to the way they influence, and
are influenced by, the demographic processes of
mortality, fertility and migration. Changes in
the age and sex structure of a population affect
all social institutions. Virtually everything
varies by age and sex.
7
The Definition and Measurement of Age Age is
the estimated or calculated interval of time
between the date of birth and the date of the
census, expressed in complete solar years
(U.N.). In most censuses and surveys, the
respondent is asked to give his/her current age
as well as the date of birth. Adjustments are
then usually introduced by clerks and officials
if the respondents current age does not
correspond to the age denoted by the date of
birth. This tends to minimize the phenomenon of
age heaping.
8
Whipples Index 101.7
9
Whipples Index 330.8
10
The Definition and Measurement of Sex Sex is
also an ascribed characteristic, yet for the most
part unchangeable. With but a few exceptions, it
is fixed at birth. When a baby is born its sex is
determined on the basis of the newborns genital
tubercle (penises ranging in length from 1.14
inches to 1.77 inches clitorises from 0.079
inches to 0.335 inches ).
11
When the length of the tubercle is between these
two average ranges, sex determination is open for
discussion and decision-making by the parents and
medical workers. But even in such extreme
situations (1-2 cases per 1,000), sex assignment
is usually made soon after birth, and most often
is permanent. The census definition of sex
therefore is usually not problematic because
everyone knows his/her sex, and it is easily
ascertainable.
12
The sex ratio (SR) is the principal measure of
sex composition used in demography and in
technical studies. It is usually defined as the
number of males per 100 females
A sex ratio above 100 indicates an excess of
males, whereas an SR below 100 indicates an
excess of females.
13
Most societies have sex ratios at birth (SRBs)
between 104 and 106, i.e., 104-106 boys are born
for every 100 girls. This biologically normal SRB
is likely an evolutionary adaptation to the fact
that females have higher survival probabilities
than males. China, Taiwan and South Korea, and
some other countries, now have abnormally high
SRBs. Since at every year of life males have
higher age-specific death rates than females,
slightly more males than females are required at
birth for there to be around equal numbers of
males and females when the groups reach their
marriageable ages. Biology thus dictates that the
age-specific SR will be highest at the very young
ages, starting around 104-106 at age 0, and
should then decline with age, attaining a value
of around 100 for persons in their late 20s and
continuing to decline to levels around 50 or 60
in the oldest ages. (See, later, the several p-p
slides of sex ratios by age.)?
14
(No Transcript)
15
Sex Ratio at Birth by Parity, China, 2000   Total
SRB, 119.9 1st Parity SRB 107.1 2nd Parity
SRB 151.9 3rd Parity SRB 159.4 SOURCE 2000
Population Census of China, State Statistical
Bureau, August 2002
16
(No Transcript)
17
(No Transcript)
18
How Many Extra Boys in China ?

• There have already been born in China around 33
  million extra Chinese boys, who when they reach
  marriage-age, will be seeking Chinese females to
  marry.
• These extra boys will be unsuccessful in their
  courtship pursuits.
• What will all these extra boys do when they
  cannot find brides?

19
If the Boys Dont Marry, What Might Happen?

• Mail-order Brides (not likely in China)
• Increased homosexuality (unlikely)
• Increased prostitution (yes)
• Bachelor ghettos (definitely yes)
• Banditry (maybe, more so perhaps in South Korea)
• Revolution (who knows?)
• Polyandry (unlikely)
• Unprecedented spread of HIV (yes,
• esp. in China)

20
(No Transcript)
21
(No Transcript)
22
The Population Pyramid A populations age and
sex structure may be considered as a map of its
demographic history. Persons of the same age
constitute a cohort of people who were born
during the same year (or period) they have been
exposed to similar historical facts and
conditions in the nation. Sometimes these
experiences will differ depending on sex. For
instance, males tend to have more war casualties
than females. The age and sex structure of the
whole population at a given moment may be viewed
as an aggregation of cohorts born in different
years.
23
A graphic representation of the age structure of
the population is the age-sex pyramid, or
population pyramid. It shows the different
surviving cohorts of people of each sex in the
country. A pyramid is one of the most elegant
ways of presenting age and sex distribution data
graphically. A population pyramid looks like
two ordinary histograms placed on their sides and
back to back. Ages start with zero at the base
and climb to the old ages at the top. Females are
pictured on the right, and males on the left. The
age-sex data in population pyramids are usually
graphed in 5-year intervals, although they may
also be graphed in single years.
24
Some Interesting Pyramids

• of Countries
• Texas Counties

25
Source INED, 2007
26
Source McFalls, 2006
27
Llano County, a retirement and natural decrease
county on Lake LBJ, had almost twice as many
deaths than births in 2004, 273 deaths vs. 144
births.
28
Coryell County is home of Fort Hood and five
female prison units 28 of the countys males
are aged 20-29
29
Collin County (suburban county North of Dallas)
30
(No Transcript)
31
(No Transcript)
32
Over 30 of Walker Countys population is male
aged 20 to 44. It is the home of Sam Houston
State University, and six male prison units,
including the death row unit of Texas.
33
Brazos County is home to Texas AM (45K students)
and Blinn College (8.2K students). One-quarter of
the countys population is aged 20-24. Almost 45
of the county is aged 15-29.
34
The UAE is more than 70 foreign-born. The
country wont release the data.
Source McFalls, 2003
35
US is 12 foreign-born Texas, 14, Harris
County 22.2.
United States
McFalls, 2005
36

Bahrain is 40 foreign-born. Consider the age-sex
differences, FB vs. natives.
SOURCE Tabutin and Schoumaker, 2005.
37
Another way to view pyramids

• Birth Cohorts

38

• BIRTH COHORTS, United States
• New Worlders
• (born from 1871 through 1889)
• 2. Hard Timers
• (born from 1890 through 1908)
• 3. Good Warriors
• (born from 1909 through 1928,)
• 4. LUCKY FEW
• (born from 1929 through 1945)
• 5. Baby Boomers
• (born from 1946 through 1964
• 6. Generation X
• (born from 1965 through 1982)
• 7. New Boomers
• (born from 1983 through now)

39
Age-Sex Structure of U.S., 2000
Hard Timers, thru 1908
Good Warriors, 1909-1928
Lucky Few, 1929-1945
Baby Boomers, 1946-1964
Generation X, 1965-1982
New Boomers, 1983 to now
40
Germany, 1889, 1980, 2000

• This German stamp is a good example of the way in
  which an everyday item such as a postage stamp
  can communicate demography is destiny. From
  this stamp one could think about the pros and
  cons of future health care or retirement
  programs, or whether to open or close the border
  to foreign workers.

41
Age-Sex Distributions

• Projected Populations
• the U.S., Texas,
• Harris and Brazos Counties

42
United States, 2050
43
United States, 2100
44
Texas, 2000 and 2030
45
Age-Sex Structure of Texas, 2006 Projected
2040
Texas will be older in 2040 than today. Old-age
dependency will be much higher in 2040 than
today.
46
(No Transcript)
47
(No Transcript)
48
(No Transcript)
49
Consider very high old age dependency of Anglos
in Harris County in 2040.
50
(No Transcript)
51
(No Transcript)
52
Look at evidence of much higher number of young
children (higher fertility) of Hispanics in
Harris County, compared to nonHispanics.
53
Hispanic Women Have the Highest Fertility Among
Major U.S. Racial and Ethnic Groups.
Fertility Trends in the United States, by Race
and Ethnicity 1991 and 2005
Source Centers for Disease Control and
Prevention, National Center for Health Statistics.
54
Women in the United States Have More Children on
Average Than Women in Europe.
Fertility Trends in Europe and the United States
1980-2006
Source National statistical agencies.
55
(No Transcript)
56
(No Transcript)
57
(No Transcript)
58
(No Transcript)
59
What about the Situation of

• Age and Race/Ethnicity
• in Texas and the U.S.
• in the Future?

60
Percent of Texas Population by Age Groupand
Ethnicity, 2000
53 Anglo, 32 Hispanic, 12 Black, 3 Other
61
Projected Percent of Net Change Attributable to
Each Race/Ethnicity Group for 2000-2040
62
Percent of Texas Population by Age Groupand
Ethnicity, 2040
25 Anglo, 58 Hispanic, 8 Black, 9 Other
Percent
Projections are shown for the 1.0 scenario
63
Majority minority populations

• In 1980 only Hawaii and the District of Columbia
  had more than 50 percent of its population
  minority, i.e., they were Majority minority
  states. By 2000 California and New Mexico had
  become Majority minority. In 2000, 77 percent of
  Hawaii was minority, 72 percent of Washington
  D.C., 55 percent of New Mexico, and 53 percent of
  California.

64
How about Texas?

• In 2000 Texas was around 53 Anglo, but became a
  Majority minority state in 2004.
• The five states of Arizona, Georgia, Maryland,
  Mississippi and New York are next in line to
  become Majority minority states they all had
  minority populations of over 40 percent in 2004.

65
The Future?

• By the year 2050, the U.S. population will number
  around 440 million people. The Anglo component,
  comprising 69 percent of the population in 2000
  and 67 percent in 2005, will have dropped to 47
  percent of the total.
• The United States in 2050 is projected to be a
  Majority minority country. Hispanics will
  comprise 29 percent of the country, Blacks 13
  percent, and Asians 9 percent.
• Almost one in five Americans (19 percent) in 2050
  will be foreign-born, a significant increase from
  the 12 percent in 2005, and higher than the
  historic peaks for immigrants as a share of the
  U.S. population, 14.8 percent in 1890 and 14.7
  percent in 1910.

66
Race/Ethnicity, US, 1960, 2005, 2050
67
Median Age in the United States and Texas,
1900-2000
68
Percent of Persons 65 Years of Age and Older in
Texas Counties, 2000
69
Percent of Persons 65 Years of Age and Older in
Texas Counties, 2040
Assuming rates of migration equal to 2000-2004
70
Texas Counties with 50 Percent or More of Their
Total Population That is Angloin 2000 and
Projected for 2040 Under Alternative Projection
Scenarios
71
End of Presentation June 19, 2008