152 



THE OUTLOOK FOR TIMBER IN THE, UNITED STATES 



Table 116.— Headship rates by age class, 1940-70, with projections to WOO 



[Percent] 



Year 



Age class 



15-19 



20-24 



25-29 



30-34 



35-44 



45-54 



55-64 



65 and 



over 



1940 



0.6 

 1. 2 

 1.8 

 1.8 



11. 3 

 16. 1 



22. 1 



23. 1 



28. 2 

 32. 9 

 39. 6 

 44. 6 



37.7 

 39.9 

 45.0 

 48.4 



44. 6 

 44. 8 

 48. 4 

 50.4 



50. 7 

 49. 2 

 52. 6 

 52. 8 



54.0 

 52. 2 

 56.2 

 58. 3 





1950 



56.8 



1960 



52. 8 



1970 



56. 1 





62.9 



Low projections 



1980 

 1990 

 2000 



1.9 

 2.0 

 2. 1 



24. 4 



25. 7 

 26.5 



46. 2 



47. 5 



48. 2 



49. 3 

 49. 6 

 49. 8 



49. 3 

 51. 1 

 51.3 



50. 9 

 53. 2 

 53.4 



58.5 

 58. 7 

 58.9 



64.0 

 64. 9 

 65.4 



Medium projections 



1980 

 1990 

 2000 



2.0 

 2. 2 

 2.4 



25.0 

 26. 5 

 27.6 



46. 7 



48. 2 



49. 3 



49. 8 



50. 7 



51. 2 



51. 5 



52. 2 

 52. 5 



53. 1 

 53.3 

 £3.5 



59. 

 59. 3 

 59. 5 



64.5 

 65.8 

 66.7 



High projections 



1980 

 1990 

 2000 



2. 1 

 2.4 

 2. 7 



25. 9 

 27. 9 

 29. 1 



47. 1 



49. 



50. 2 



50. 1 



51. 2 

 51. 9 



51.7 



52. 6 



53. 1 



53. 3 

 53.6 

 53.8 



59. 2 

 59.6 

 59.8 



64.9 



66. 3 



67. 3 



Note: Headship rate is the percentage of persons in 

 each a^e class that heads a household. 



Sources: 1940-50— Campbell, Burnham O. Population 

 change and building cycles. Univ. 111. Bull. 64(27): 46- 



Headship in relation to per capita 

 disposable personal income (in 1967 dollars) 

 for population 18 years of age and older 





1930 J.- 

 1930 19<0 \,J ^f 

 \ / 1 '•* 



1933 



1970 

 I 



1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 

 PER CAPITA DISPOSABLE PERSONAL INCOME | DOLLARS | 



Figure 60 



housing units, such as single-family and multi- 

 family units. 



Past fluctuations in the number of births 

 result in fluctuations in projected numbers of 



49. 1966; 1960-2000— Marcin, Thomas C. Projections of 

 demand for housing by type of unit and region. U.S. Dep. 

 Agr., Agr. Handbk. 428, 76 p. 1972. 



households by age class and related changes in 

 types of housing units demanded. As a result of 

 the large number of births in the 1950's, for 

 example, nearly 58 percent of the projected 

 increase in households in the 1970's will have heads 

 under 35 years old. Over four-fifths of these 

 will be in ages 25-34. In contrast, the number of 

 households with heads 35-44 years old will 

 remain virtually unchanged. After 1990, on the 

 other hand, most of the growth in the projected 

 numbers of households will be in the older age 

 classes. 



Housing Replacements 



A second major component of housing demand 

 is the replacement of units lost from the housing 

 inventory. During the 1960's replacements ac- 

 counted for about 40 percent of the total number 

 of housing units provided. 



In the past four decades, gross replacements 

 have increased from an average of about 100,000 

 units to nearly 700,000 (table 118). This rise 



