Investors' Reaction to a Reform of Corporate Income Taxation Dennis Voeller z (University of Mannheim) Jens M¨uller z (University of Graz) Draft: November 2011 Abstract: This paper investigates the stock market response to the corporate tax reform in Germany of 2008. The reform included a decrease in the statutary corporate income tax rate from 25% to 15% and a considerable reduction of interest taxation at the shareholder level. As a result, it provided for a higher tax benefit of debt. As it comprises changes in corporate taxation as well as the introduction of a final withholding tax on capital income, the German tax reform act of 2008 allows for a joint consideration of investors' reactions on both changes in corporate and personal income taxes. Analyzing company returns around fifteen events in 2006 and 2007 which mark important steps in the legislatory process preceding the passage of the reform, the study provides evidence on whether investors expect a reduction in their respective tax burden. Especially, it considers differences in investors' reactions depending on the financial structure of a company. While no significant average market reactions can be observed, the results suggest positive price reactions of highly levered companies. Keywords: Tax Reform, Corporate Income Tax, Stock Market Reaction JEL Classification: G30, G32, H25, H32 z University of Mannheim, Schloss Ostfl¨ugel,D-68161 Mannheim, Germany,
[email protected]. z University of Graz, Universit¨atsstraße15, A-8010 Graz, Austria,
[email protected]. 1 Introduction Previous literature provides evidence that companies adjust their capital structure as a response to changes in the tax treatment of different sources of finance.