On the budget deficit under economic growth -Toward a mathematical model of MMT (Modern Monetary Theory)-

We will show, using a simple two-periods overlapping generations (OLG) model with bequest motive in which goods are produced solely by labor in a monopolistically competitive industry, that a continuous budget deficit is necessary to maintain full-employment under economic growth driven by technological progress. Since the budget deficit to maintain full-employment must be continuous, it should be financed by seigniorage not by public debt. Budget deficit is necessary under growth because of deficiency of the consumptions of the older generation. This budget deficit is not debt and does not need to be redeemed. If the budget deficit is excessive, inflation will be triggered. About this excessive budget deficit that has caused inflation, only the excess portion should be reduced, and there is no need to make up for past excesses by creating surpluses or reducing deficits. We also show that insufficient government expenditure causes involuntary unemployment