Very Simple Mathematical Model of MMT (Modern Monetary Theory)

摘要

The purpose of this paper is to provide a concise theoretical and mathematical foundation for the major parts of the debate in the recently discussed school of economics called Modern Monetary Theory (MMT), while maintaining the basics of the neoclassical microeconomic framework, such as utility maximization of consumers using budget constraints and utility functions, and equilibrium of demand and supply of goods under perfect competition with constant returns to scale technology. By a two-periods overlapping generations (OLG) model in which the economy grows by technological progress, we will show that: 1) We need a budget deficit to achieve full employment with constant price when the economy grows by technological progress. This budget deficit should not be offset by future surplus;2) A budget deficit that exceeds the level necessary to maintain full employment in a growing economy with constant price will cause inflation. A stable budget deficit is required to prevent further inflation;3) A budget deficit that is insufficient to maintain full employment will cause a recession with involuntary unemployment. A budget deficit larger than the one necessary and sufficient to maintain full employment without a recession can overcome a recession caused by insufficient budget deficit and restore full employment. The deficit created to overcome the recession should not be offset by subsequent surpluses, since full employment can then be maintained through constant budget deficits.