> In practice, progressive tax curves and incentive programs let politicians meddle. Is there cross-country comparative empirical evidence for that? My hunch i

> In practice, progressive tax curves and incentive programs let politicians meddle. Is there cross-country comparative empirical evidence for that? My hunch is that very obscure tax curves (trapezoids and what not with layers of ad hoc edge cases) are vulnerable to meddling. But I doubt there's a general meddle-ability difference between simple forms of progressivity vs flat.