Depreciation and intergenerational altruism in the private provision of public goods

The static model of the private provision of public goods is refuted by empirical and experimental evidence which shows that contributions are above the levels predicted by the theory. The model is reconsidered here in an intertemporal framework that allows the formation of a stock of public good over time and admits intergenerational altruism into preferences. Both of these factors affect the level of private provision. An intertemporal version of the Samuelson rule is derived and it is shown that, for some parameter values, the provision level determined by this is matched by private provision. For other parameter values, it is shown how a system of taxation can achieve the optimum.