Beale, Calvin L.

English

Research Papers in Economics

SIX DEMOGRAPHIC  SURPRISES
Calvin L. Beale
Economic Development Division, ERS, USDA
If demographic trends were as regular and predictable  as population
analysts would like to them to be, demography would be a dull science.
Moreover,  despite  the  increased  sophistication  of forecasting  models
and  computing  equipment,  human behavior  continues  to  change  in
ways that  seem  to  defy  prediction,  even  over  the course  of a  single
decade.  While  we are still in the early years of the 1980s, I think it is
instructive  (and  chastening)  to review  ways  in  which  the  course  of
American  demographic  events in the  1970s  deviated from what had
been  foreseen  at the beginning  of that  decade.  Lo,  six demographic
surprises  - although  they  can  easily  be subclassified  into  a larger
number  of component  surprises.
1. The Birth Rate.  In  1970,  the Bureau  of the  Census  issued  for
projections  of the  United  States population  in which  the  forecast  of
births for the 1970s ranged from 37.3 to 48.4 million. A year later the
bureau revised its estimates upward,  on the premise that the average
age of childbearing would drop. These four new estimates ranged from
40.1 to 49.3 million decade births. Actual births for the decade proved
to be  33.2 million.  All  eight series  of projections  exceeded the actual
number  by a substantial  margin, and the direction  of the  revision  in
1971 proved to be the opposite of the  course of events underway.  The
C  and  D  series  of 1971,  which  were  probably the  most widely  used,
were  39  and  30  percent,  respectively,  above  recorded  births.  By  the
mid-1970s,  the median  age of mothers  had begun to rise rather than
fall.  Several sub-surprises  can be said to have contributed  to the low
number  of births,  such as the rise in age  of marriage,  the  decline  in
expectation  of marriage,  the extent of deferment  of childbearing,  and
the legalization  of and increase in abortions.
2.  The Death Rate. In the  same  Census  Bureau projections  series,
only one  assumption  of mortality  levels was used.  Thus the range of
deaths varied  narrowly,  depending on the number of births and  sub-
sequent child mortality. The range of the 1970 and  1971 death projec-
tions for the decade was from 20.8 to 21.3 million.  The observed number
was 19.3  million.  Again, all series were high.  If the projections of the
C and D series of 1971 are used as a standard for comparison,  projected
deaths exceeded  actual by  10 percent.
3Improvement in life expectancy  was slow in the  1960s (rising only
seven-tenths  of a year during the decade).  Perhaps influenced  by this
fact, the census  projections used a high series  of mortality rates  that
assumed  life expectancy  would increase  by  only about half of a year
in the  1970s,  or less than in the  1960s.  Instead,  death rates fell  and
life expectancy rose by 3.4 years, nearly seven times the projected rate.
In fact, it reached  a level well above that assumed for the year 2000.
Thus,  even mortality - long touted by  demographers  as readily  pre-
dictable over the near term - departed significantly  from its charted
course  in  less than  a  decade,  with  the  pace  of mortality  reduction
taking the  opposite  trend from the forecast.  Much  of the mechanism
seems to have been rapidly lowered death rates from heart disease and
strokes.
3. Household Size. A third surprise of the 1970s was the accelerated
decline  in average  household  size.  Here was a trend whose  direction
was correctly foreseen. With the exception of a period during the baby
boom of the  1950s, household size had been declining for a long time.
During the  1960s,  average household  size  dropped from 3.33  to  3.14
persons,  or by  5.7 percent.  In 1968,  the Bureau  of the Census issued
projections  of  1980 household  size ranging from  2.88 to 3.28  persons.
(There were eight different  series, depending  on birth rate, marriage,
and  household  formation  assumptions.)  The two  most  favored  series
ranged from  3.08 to 3.19 persons. By 1980, however,  actual household
size had plummeted  to 2.76 persons, well  below any of the series  and
a drop of 12.1 percent  since 1970.  The projected  decline would almost
certainly  have  been  lower,  if the bureau  had had  the  benefit  of the
1970 Census in making its projections. But, the extent of the disparity
between the actual and projected  1980 numbers illustrates clearly the
strong  unpredictable  deviation  from  previous  trend  line  that devel-
opments in living arrangements, fertility, and (to a lesser extent) mor-
tality produced on household size in the 1970s. In particular, the creation
of new nonfamily  households  and of one-parent  family households -
which are typically rather small in size - proceeded far more rapidly
than had been  foreseen.
4. The Regional Shift in Population. The migration  of people from
the North  to the  South and West  was-  like the trend in household
size - a continuation  of a past trend that was predicted  in direction
but surprising in its dimensions.  By 1980, more than half of the pop-
ulation lived in the census South and West, and for the first time the
center of population had crossed the Mississippi River - neither event
predicted. The most ambitious set of regional projections  for the 1970s
was a seven-volume  work prepared by the Bureau of Economic Analy-
sis (BEA), Department of Commerce,  for the Water Resources  Council.
This material  was put together in 1972 - two years into  the decade
- and published in 1974.
At  the  national  level  it was  keyed to the  Census Bureau's  lowest
4new projection and came within three million of the 1980 Census total
population.  The regional  expectations  were  so far  off,  however,  that
by  1980  the  Southern  New  England,  Mid-Atlantic,  and  East  North
Central States had grown  in population by only one-seventh  as much
as projected (1.1  million instead of 7.6 million), the West had increased
by  more than  double the  amount  forecast  (8.3 million  instead  of 4.0
million),  and  the  South's population  had risen  by three-fifths  more
than predicted (12.5  million instead  of 7.8 million).  To express it an-
other way, it was predicted in 1972 that the northern industrial states
would  garner  39  percent  of the nation's  population  growth  over  the
rest  of the  decade.  But  so  rapidly  did  both  the real  and  perceived
advantages of living in this region fall, that only 6 percent of all growth
actually took place there. The South and  West,  which were expected
to  obtain  60  percent  of national  growth,  wound  up  with 92  percent.
Despite the  poor quality  of these  projections,  their use was required
in some federally  sponsored  planning activities.  Thus the well-inten-
tioned inability to foresee regional  shifts was not without its practical
consequences.
5.  Growth of Rural and Small Town Population. If ever a piece  of
conventional  wisdom existed  about the dynamics of population move-
ment in  20th  century  America,  it was  that population  flowed  from
rural to urban area. The modern history  of the country was,  in many
respects,  a history of urbanization.  It was obvious in the latter part of
the 1960s that the farm population of the United States - which was
the major source of rural-to-urban  migrants - had declined to a level
that did not  allow further  outflows anywhere  near  as large  as those
of the past. Still, neither the demographic forecasting at the beginning
of the 1970s nor the public and academic  discussions of the time gave
any hint of an imminent reversal in the traditional migration pattern.
The 1972 BEA projections estimated an 11.4 percent growth for met-
ropolitan counties  in the 1970s, compared with 5.3 percent growth for
nonmetropolitan  counties.  A relative  differential  of about this extent
was projected  to continue  for the  rest of the projection  period,  which
extended until 2020.
In reality, at the very time the forecasts  were made, the net flow of
migration  had reversed  and  more  people  were moving  into  nonmet-
ropolitan  areas than  out  of them.  From  1970  to  1980,  metropolitan
counties increased in population by  9.8 percent, but the nonmetropol-
itan counties  grew  by  15.8 percent,  or three times the projected  rate.
The prevailing  framework  of thought had  not anticipated  the rise  of
nonpecuniary  motivations  for  residential  location  that characterizes
so much  of the nonmetropolitan  growth trend,  nor had it adequately
assessed  the  decentralization  of  manufacturing  and  other  develop-
ments that led to growth of rural and small town employment  oppor-
tunities.
6. The Role of Illegal and Refugee Immigration. By its very nature,
5the amount of illegal immigration into a country is difficult to estimate
much less to predict. Whatever the true amount into the United States
may  be the  consensus  seems  to  be that  it rose to  major proportions
during the  1970s,  and thus became  a significant factor  in population
growth.  For many  years, the  Census Bureau has  used a projection  of
400,000  annual  net  inmovement  of people from abroad,  but this  has
not allowed for illegal entries. The phenomenon  is certainly not new,
but its increase  is beyond earlier  expectations,  and is  commonly  be-
lieved  to  account for that part of the 5  million  higher-than-expected
1980  Census count that is not due to improved  enumeration.
A further  source of unexpected  increase has  come  from refugee  ad-
missions.  No  one would utter the unutterable  in 1970 that the Viet-
namese, Cambodian, and Laotian governments would fall, followed by
outmovement  of several  hundred thousand  people.  The influx  of Cu-
bans  to  the  United  States  in  1980  was  another  example  of sudden
refugee  immigration  of significant proportions.
It is not my point in recounting these demographic  surprises to im-
ply  criticism  of the  forecasters  who  made  the  projections  discussed
(although  I  think  some  is  merited  in  particular  cases).  Rather,  the
predictions did typically reflect the prevailing wisdom. I view the prob-
lem  as generic.  The demand for  projections  is  insatiable.  The ability
to make them accurately is limited even by people of good credentials.
What will the surprises of the 1980s  be? I wish I knew.
6

SIX DEMOGRAPHIC SURPRISES

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