DEMAND FOR TIMBER PRODUCTS 



151 



Table 115. — Households and household formations, 

 by decade, 1920-70, with projections to 2000 



Year 



Total 

 house- 

 holds 



Average 

 household 



annual 

 increase l 



Persons 



per 



household 



1920 



Thouiandt 

 24, 436 

 30, 002 

 34. 964 

 42, 969 

 53, 024 

 63, 417 



Thousands 



Percent 



Number 

 4.3 



1930 

 1940 

 1950 

 1950 

 1970 



556.6 



496.2 



800. 5 



1, 005. 5 



1, 039. 3 



2. 1 

 1.5 

 2. 1 

 2. 1 

 1.8 



4. 1 

 3.8 

 3.5 

 3.4 

 3.2 





Low projections 







1980 

 1990 

 2000 



76, 400 

 88, 500 

 97, 700 



1, 330. 

 1,210.0 1 

 920.0 



1.9 

 1.5 

 1.0 



3.0 

 2.8 

 2.7 



Medium projections 



1980 

 1990 

 2000 



76, 800 

 89, 600 

 99, 900 



1, 370. 

 1, 280. 

 1, 030. 



2.0 

 1.6 



1. 1 



3.0 

 2.8 

 2.8 



High projections 



1980 

 1990 

 2000 



77, 200 



90, 400 



102, 700 



1,410.0 

 1, 320. 

 1, 230. 



2. 1 

 1.6 



1.3 



3.0 

 2.9 

 2.9 



1 Average annual increase for decade ending on Decem- 

 ber 31 cf preceding year for projections (see note below). 

 Decade average for 1970-80 is calculated for 10-year 

 period based on 9.75 years. 



Note: Historical data on households are for decennial 

 census dates, generally April 1. Projected number of 

 households are estimates as of January 1 of given year. 



Sources: U.S. Department of Commerce, Bureau of the 

 Census. 1920-60 — United States census of housing, 1960. 

 HC(1)-1. 1963; 1970—1970 Census of housing. Ser. HC 

 (Vl)-l. 1971. 



Projections: U.S. 

 Service. 



Department of Agriculture, Forest 



largely reflects a substantial increase in per capita 

 disposable personal income and social changes in 

 this period. 17 



Projections of headship rates, based on past 

 relationships with per capita income and expecta- 

 tions about further social changes, show a con- 

 tinuing rise for all age classes through the 

 projection period (table 116, fig. 60). 



17 For a more complete discussion of the factors affecting 

 changes in headship rates tee Campbell, Burnham O. 

 Population change and building cvcles. Univ. 111. Bull. 

 64(27) :46-49. 1966. 



Headship rates by age class, 1950 and 1970, 

 with projections for 2000 



2000, high projection ^.j 



15-19 20-24 2529 30-34 3544 4554 5564 65 



and over 

 AGE CLASSES 



Figure 59 



Projected household jormations. — Projected 

 household formations — based on the assumed 

 headship rates and Census projections of popula- 

 tion by age class — rise in the 1970's to a peak in 

 the early 1980's, then decline through the rest of 

 the 1980's and early 1990's. After that, projections 

 depend increasingly on the population and eco- 

 nomic assumptions adopted. Under the medium 

 and high assumptions on population and economic 

 growth, there would be a substantial rise in house- 

 hold formations after 1990. 



The relatively limited differences between the 

 high, medium, and low projections of household 

 formations in the 1970's and 1980's largely reflect 

 effects on headship rates of economic growth 

 assumptions. After 1990, however, alternative 

 projections diverge more and more as effects of 

 different rates of population growth become 

 increasingly important. 



Numbers of persons per household, which are 

 inversely related to headship rates, have declined 

 from 4.3 in 1920 to about 3.2 in 1970. The pro- 

 jected headship rates indicate a further decline 

 to 2.8 (medium level) in 2000 (table 115). 



Household formations continue to be a major 

 source of demand for housing through the pro- 

 jection period (table 117, fig. 61). However, they 

 decline in importance, relative to replacements, 

 falling from 59 percent of total projected demand 

 in the 1960's to about 39 percent in the 1990-2000 

 decade. 



Households by age class. — The distribution of 

 households by age class is an important deter- 

 minant of demand for the various types of 



