Malthusfs Criticism of Adam Smith and Dynamic Mechanism of Population in the First Edition of Principle of Population

Two issues are addressed in this paper. First, we analyze with a simple mathematical model Thomas Robert Malthusfs critique of Adam Smith, the most theoretically discussed part in the first edition of Principle of Population. Second, by introducing a differential equation for the dynamics of price, unlike most of the other present scholars, we explain Malthusfs dynamic mechanism of population more in detail, and thereby reconsider and reinforce his idea of encouraging investment in agriculture discussed in his critique of Smith. Thereby, we show that under the assumption set forth by Malthus, economic development created by investment in agriculture is more desirable compared to investment in manufacturing, in the view of social welfare; that Malthusfs idea implied some type of precursory Keynesian idea, that is, the creation through policy of effective demand to agriculture, not to manufacture, leads to economic growth with improvement in social welfare.