Laura A. Wheeler (Georgia State University, Andrew Young School of Policy Studies) has published The Potential Effect of Eliminating the State Corporate Income Tax on Economic Activity, 39 State Tax Notes 705 (Mar. 6, 2006), also available on the Tax Analysts web site as Doc 2006-2020, 2006 STT 43-10.  Here is the Conclusion:

Would the elimination of the corporate income tax lead to increased employment and a higher level of investment in Georgia? Based on the research reviewed above, we can say that low state corporate income taxes have a positive effect on investment and employment in a state. It’s also expected that the elimination of the corporate income tax would have a larger and faster effect on investment in the state than on employment. That is because of the greater responsiveness of investment to changes in the tax rate as documented in the academic literature. The controversy concerning the elimination of the corporate income tax resides around the magnitude of the effect on investment and employment. Our best estimate leads us to expect an increase in investment for the state of around 0.6 percent, or $1.8 billion, and an increase in employment of 17,000 additional new jobs. In addition to those estimated employment and investment effects, the elimination of the corporate income tax may send a signal to businesses that the state is business-friendly and willing to support business activities. The size of that "WOW" effect in terms of additional employment and investment can’t be estimated at this time because no state has yet eliminated its corporate income tax. But it’s expected to have some small positive influence on employment and investment in the state.

The academic research also indicates that public expenditures are important to firms, and studies that include public expenditures in their empirical models have found that corporate taxes affect both investment and employment at the state level. But the correct interpretation of those results leads not to an elimination of the corporate income tax but to an understanding that there’s some optimal balance of taxes and nontransfer-type public expenditures valued by firms. Therefore, those studies lead to the conclusion that an elimination of the corporate income tax should be accompanied by an increase in revenue from another tax or by a decrease in public expenditures spent on income support programs so that the public services valued by firms aren’t diminished.