The Pew Center on the States, Evidence Counts: Evaluating State Tax Incentives for Jobs and Growth:

In their quest to strengthen their economies, particularly in the wake of the Great Recession, states continue to rely heavily on tax incentives, including credits, exemptions, and deductions, to encourage businesses to locate, hire, expand, and invest within their borders. Yet half the states have not taken basic steps to produce and connect policy makers with good evidence of whether these tools deliver a strong return on taxpayer dollars.

Research by the Pew Center on the States concludes 13 states are leading the way in generating much-needed answers about tax incentives’ effectiveness. Twelve states have mixed results. The other 25 states, along with Washington, D.C., are trailing behind.