Higher Tuition, More Grade Inflation
In many applications, small data sets make it challenging to precisely identify such a kink in the data. But with millions of observations at their disposal, the authors are able to conclusively reject any effect of the tax credits. In other words, there were no kinks in enrollment at the point that tax credits fade-out.
In another paper, Bulman and Hoxby use a regression-discontinuity design to estimate the effects of the tuition tax deduction for families around the maximum income cutoff for eligibility. 2 Again, they find no evidence that the deduction increases college enrollment. They also find no effect of the deduction on enrollment intensity, college choice, tuition paid, or student debt.? More