There is no general consensus about what sustainable development means. We seek to clarify the meaning and utility of the concept by focusing on forest resources in countries possessing higher levels of per capita incomes. The meaning of sustainable development becomes complex when one asks what social goals are being pursued, what types of stability are permitted, whether amenities and commodities should receive equal consideration, and to what landbase the concept should be applied. A simulation/linear programming model of California's private forest resource is used to demonstrate that strict decade-to-decade 'even-flow' stability of production may result in lower aggregate levels of output over a prolonged planning period, with ending levels of the stock resource that are scarcely greater than when output is permitted to vary over the planning period. The model was also used to show that greater levels of output and ending stocks are possible when the land base for sustainability assessment is not a restrictively small geographical area or a single class of ownership. In the case of National Forests and other public lands, the application of the sustainable development concept is significantly more complex because of the importance of amenity values and because of the inherent conflict between development and the preservation of ecosystems in a pristine state.