This chapter explores the options available to hunters and gatherers for achieving environmental sustainability and for their economic development by applying new economic modelling. It pays particular attention to the consequences of these options for differences in the leisure-preferences of foragers and variations in their aspiration levels for income. Malthusian population dynamics is used to explore these relationships. The scope for income inequality, for the generation of an economic surplus, and for the appropriation of this surplus within tribal groups are considered. Variations in the economic and resource conditions experienced by hunters and gatherers influenced their social structures, and vice versa. Hence, differences in the social structure of Northwest American Indian tribes and that of Australian Aborigines are briefly covered. Implications of this for natural resource conservation and for the extraction of an economic surplus by these different social groups are addressed.