second major wave of concern about natural resource policy since World War II and the fourth since Malthus [28]. The first postwar period of concern occurred about 1950 and emphasized the relationship between available and projected resources and economic growth. The oft-quoted but little-heeded reports1 of the President's Materials Policy Commission [23] and the Water Resources Policy Commission [24] were basically concerned with scarcity or, in contemporary jargon, short-falls. Scarcity was defined more as a physical concept than an economic one, relating production capacity and reserves to projected needs. The second postwar wave, according to Ruttan, shifted from traditional concern for adequacy of the natural resource base to stress on environmental consid-