ABSTRACT
This chapter focuses on population theory. Some of the contributions to pre-Malthusian population theory are indeed both interesting and profound — it is difficult to think of a more vivid statement of the central core of the matter than Cantillon's dictum that 'men multiply like mice in a barn' when subsistence is available. It was Thomas Robert Malthus who made the main impact on thought. It is often said that the famous contrast between the geometrical and arithmetical ratios of increase of population and food respectively was false and misleading and, furthermore, that this argument has nothing to do with the idea of diminishing returns. Malthus's fundamental theory of depression and under-employment is certainly not Keynesian. Over-saving for him means over-investment — using investment in the Keynesian sense. Depression arises because too much saving gets invested. He goes out of his way to deny the likelihood of hoarding.
