This paper investigates the impact of tax base mobility on local taxation. We first develop a theoretical model in order to examine the connection between local business property taxation and tax base mobility within a metropolitan area. We find that decreasing capital intensity in the tax base increases the business property tax rates unambiguously. We then test this result using a French reform, which changes the composition of the main local business tax base in 2010. Estimations using Difference-inDifferences show that the reduction in the mobility of the tax base indeed results in higher business property tax rates. Housing tax rates were not affected by the reform.