Source: Brian Galle, Public Finance Review, Published online before print March 22, 2016
From the abstract:
We investigate the effects of variations in the value of the charitable contribution deduction on nonprofit firm behavior, including exploring for the first time the effects of the tax price of giving on fund-raising. We find that a 1 percent increase in tax subsidies is correlated with a 2.0 percent increase in fund-raising, while the elasticity of real charitable output to changes in tax price is less than one in absolute value for most firms. We derive a new equation for treasury efficiency in the presence of fund-raising and find that while our point estimates still support treasury efficiency, our confidence intervals are wide enough to allow some possibility that the deduction is not cost effective. Further, the modest elasticity of charitable output to tax price implies that tax subsidies can crowd out other revenue sources, such that the efficacy of the subsidy depends on the relative efficiency of these alternative sources.