Do government subsidies increase the private supply of public goods?

We study three different models in which public goods are supplied by private contributions. In one of these models, tax-financed government subsidies to private contributions will definitely increase the equilibrium supply of public goods. In the other two models, government subsidies are neutralized by offsetting changes in private contributions. We explain why it is that these models lead to opposite conclusions and we argue on the basis of our first model that a government that wants to use taxes and subsidies to increase total provision of public goods will be able to do so. Indeed, our model yields a surprisingly decisive comparative statics result. If public goods and private goods are both normal goods, then an increase in the subsidy rate will necessarily increase the equilibrium supply of public goods.