Beggar thy Neighbor? The In-State vs. Out-of-State Impact of State R&D Tax Credits
The paper exploits the cross-sectional and time-series variation in R&D tax credits, and in turn the user cost of R&D, available from U.S. states between 1981-2002 to
estimate the elasticity of private R&D with respect to both the within-state (internal) user cost and the out-of-state (external) user cost.
Link
http://www.frbsf.org/publications/economics/papers/2005/wp05-08bk.pdf