Public Investment and Corruption in an Endogenous Growth Model

High capital spending is favored by economists and politicians for its beneficial effects on economic growth. However, there is empirical research associating high levels of public investment with low economic growth due to corruption. I provide an endogenous growth model with Ramsey taxation that is consistent with this empirical finding. In the model, government maximizes the weighted average of consumers' utility and its own utility coming from expropriation of tax revenues. The weight determines the benevolence of the government. I show that a self-interested government sets a higher public-to-private-capital ratio than a benevolent one, reducing the productivity of public capital, in order to use more of the tax revenues for its own consumption. While a large public-to-private capital ratio increases the productivity of private investment, high taxes that come along with high public capital spending reduce the after-tax returns to private investment, causing the growth rate to be low.