Simon's 1981 book The Ultimate Resource is a criticism of what was then the conventional wisdom on resource scarcity, published within the context of the cultural background created by the best-selling and highly influential book The Population Bomb in 1968 by Paul R. Ehrlich and The Limits to Growth analysis published in 1972. The Ultimate Resource challenged the conventional wisdom on population growth, raw-material scarcity and resource consumption. Simon argues that our notions of increasing resource-scarcity ignore the long-term declines in wage-adjusted raw material prices. Viewed economically, he argues, increasing wealth and technology make more resources available; although supplies may be limited physically they may be regarded as economically indefinite as old resources are recycled and new alternatives are assumed to be developed by the market. Simon challenged the notion of an impending Malthusian catastrophe—that an increase in population has negative economic consequences; that population is a drain on natural resources; and that we stand at risk of running out of resources through over-consumption. Simon argues that population is the solution to resource scarcities and environmental problems, since people and markets innovate. His ideas were praised by Nobel Laureate economists Friedrich Hayek and Milton Friedman, the latter in a 1998 foreword to The Ultimate Resource II, but they have also attracted critics such as Paul R. Ehrlich, Albert Allen Bartlett and Herman Daly.
Simon examined different raw materials, especially metals and their prices in historical times. He assumed that besides temporary shortfalls, in the long run prices for raw materials remain at similar levels or even decrease. E.g. aluminium was never as expensive as before 1886 and steel used for medieval armor carried a much higher price tag in current dollars than any modern parallel. A recent discussion of commodity index long-term trends supported his positions.