This article analyzes empirically the main existing theories on income and population city growth: increasing returns to scale, locational fundamentals and random growth. To do this we implement a threshold nonlinearity test that extends standard linear growth regression models to a dataset on...

We take a critical look at how to assess the effectiveness of R&D tax incentives. The net welfare gain is shown to be sensitive to a certain number of parameters. In particular, the deadweight loss associated with level-based tax incentives depends on the ex-ante R&D level. We report on the...