Chapter 1. — Basic Assumptions 



This chapter presents the general basic assump- 

 tions used in making demand and supply projections 

 for outdoor recreation and wilderness, wildlife and 

 fish, forest-range grazing, timber, and water which 

 are presented in following chapters. In partial recog- 

 nition of the uncertainty about future changes, three 

 alternative assumptions are presented for popula- 

 tion, economic activity, and income. The alternatives 

 cover the range over which growth in these major 

 determinants, and the associated projections of de- 

 mand for renewable resource products, could rea- 

 sonably be expected to vary. They also illustrate the 

 sensitivity of the demand projections to changes in 

 these basic determinants. 



In making the general assumptions used here, it is 

 recognized that completely accurate predictions 

 about longrun population and economic growth, or 

 any of the other determinants of demand for or 

 supply of renewable resource products, are beyond 

 attainment. The intent is to make assumptions, 

 based on historical trends, current knowledge about 

 developments which affect these trends, and present 

 expectations about future changes which can be gen- 

 erally accepted as reasonable at this time. 



Past trends in the major determinants used here 

 result from massive social, political, technological, 

 and institutional forces that are not easily or quickly 

 changed. Barring major catastrophes, such as a 

 world war or depression, recent trends are likely to 

 persist over a considerable time. Thus, basic assump- 

 tions, derived as described, provide a realistic basis 

 for preparing an assessment for the development and 

 guidance of renewable resource policies and pro- 

 grams in 1980's. Near the end of that decade, and as 

 required by the Renewable Resources Planning Act, 

 the basic assumptions will be reevaluated; new ex- 

 pectations will be incorporated in the assessment 

 which must be submitted to Congress in 1990. 



' U.S. Department of Commerce, Bureau of the Census. Popu- 

 lation estimates and projections. "Projections of the population of 

 the United States: 1977 to 2050." Cur. Pop. Rep. Ser. P-25, No. 

 704, U.S. Government Printing Office, Washington, D.C. 87 p. 

 1977. 



2 Fertility rates indicate the number of births per 1 ,000 women 

 during their childbearing years. For a more detailed technical 

 definition, see U.S. Department of Health, Education, and Wel- 

 fare, Public Health Service. Natality statistics analysis United 

 States, 1965-67. National Center for Health Statistics, Ser. 21, 

 No. 19, U.S. Government Printing Office, Washington, D.C. 39 p. 

 1970. 



3 U.S. Department of Commerce, Bureau of the Census. Popu- 

 lation characteristics. "Fertility of American women: June 1976." 

 Cur. Pop. Rep. Ser. P-20, No. 308, U.S. Government Printing 

 Office, Washington, D.C. 75 p. 1977. 



"U.S. Department of Commerce, Bureau of Economic Analy- 

 sis. Population, personal income, and earnings by State projec- 

 tions to 2030. 25 p. 1977. 



Population 



Changes in population have an important effect 

 on the demand for outdoor recreation, wildlife and 

 fish, timber, forage, water, and the other forest, 

 range, and inland water products included in this 

 study. They also influence the size of the labor force, 

 a major determinant of the level of economic activity 

 and related materials use. 



In the five decades between the late 1920's and the 

 late 1970's, the population of the United States in- 

 creased by about 98 million people, rising at an 

 average annual rate of 1.2 percent (table 1.1, fig. 

 1.1). The most recent projections of the Bureau of 

 the Census' indicate that population is likely to con- 

 tinue to grow fairly rapidly through the projection 

 period. The Census Series II projection — the 

 medium projection of this study — shows population 

 rising by another 81 milion by 2030. In line with 

 recent trends, however, the annual rate of growth 

 declines from about 1 percent in the late 1960's and 

 early 1970's to 0.3 percent in the decade 2020-2029. 



The alternative projections (Series I and III) pre- 

 pared by the Bureau of Census show substantial 

 increases in population. However, under the low 

 projections (Series III) nearly all of this occurs prior 

 to 2010-19 decade and begins to decline in the first 

 half of the following decade. 



The decline in the rate of population growth re- 

 flects Bureau of the Census assumptions about fertil- 

 ity rates. 2 Fertility rates fluctuated widely in recent 

 decades, but since the late 1950's have fallen sharply. 

 The medium projection is based on an assumed fer- 

 tility rate of 2.1 — a level close to current birth 

 expectations of young American wives. ^ The current 

 fertility rate is below this figure and approximates a 

 level which would end population growth in the first 

 part of the twenty-first century. 



Legal immigration accounts for a significant part 

 of population growth, and the estimates shown in 

 table 1.1 includes a net addition of 400,000 immi- 

 grants each year. Legal immigration has declined 

 recently and some further reduction could result 

 from growing national concern about unemployment 

 and population pressure on resources and the envi- 

 ronment. No allowance has been made for illegal 

 immigration. 



The geographic distribution of the population has 

 a strong influence on State and regional demands 

 for renewable resources, particularly those that must 

 be produced and consumed at the same place. State 

 projections prepared by the Bureau of Economic 

 Analysis,'* are used as the basis for regional projec- 

 tions in this work. They show significant differences 



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