Sebastian Kessing WZB   University of Siegen Reichpietschufer 50 Berlin, 10785 Germany   kessing@vwl.wiwi.uni-siegen.de   http://www.wz-berlin.de/mp/mps/people/sebastian_kessing.de.htm           JEL Areas: H2 : Taxation, Subsidies, and Revenue: General H0 : Public Economics: General