Keynesian multipliers, direct crowding out, and the optimal provision of public goods

This paper studies Keynesian multipliers in a macroeconomic model with monopolistic competition. We allow public and private consumption goods to be perfect substitutes in private utility. This enables us to study the effect of direct crowding out on the size of national income, profit and employment multipliers for a given rise in real public spending. A positive real national income multiplier is obtained if consumers value public consumption less than private consumption. In addition, we determine the effective marginal cost of public funds and the optimal provision of public goods, both in the short run and in the long run.