This article discusses the common-pool problems that arise when multiple territorially overlapping governments share the authority to provide services and levy taxes in a common geographic area. Contrary to the traditional Tiebout model in which increasing the number of competing governments improves efficiency, I argue that increasing the number of overlapping governments results in “overfishing” from the shared tax base. I test the model empirically using data from U.S. counties and find a strong positive relationship between the number of overlapping jurisdictions and the size of the local public sector. Substantively, the “overlap effect” amounts to roughly 10% of local revenue.