Böserup model

E. Böserup's (1965) view that increases in population size stimulate agricultural change in subsistence societies, given no increase in land area. At the earliest stage, small families subsist through forest fallow where land is used for two years or so and is then left for twenty to twenty-five years. As population rises, bush fallowing and short fallowing are used with increasingly intense cropping and the shortening of the fallow period. Further population growth is followed by annual cropping which consists of harvesting one crop a year with a fallow of a few months only. Multi-cropping is stimulated by further population increase and is the most intensive system of agriculture. Changes in farming technology also increase yields; for example, digging sticks are replaced, first by hoes, and then by ploughs. Weeding becomes more frequent, and manuring is introduced. These changes increase labour requirements, so that, while yields per hectare rise, yields per capita remain more or less constant.

This theory runs counter to Malthus' argument that population increase is only possible after a certain level if food supplies rise. Although Böserup's thesis was developed for subsistence populations, the Green Revolution can be seen as a response to population increases.