http://elsa.berkeley.edu/~saez/saez-slemrod-giertzJEL10round2.pdf
Saez said:Abstract
This paper critically surveys the large and growing literature estimating the elasticity of taxable income with respect to marginal tax rates (ETI) using tax return data. First, we provide a theoretical framework showing under what assumptions this elasticity can be used as a sufficient statistic for efficiency and optimal tax analysis. We discuss what other parameters should be estimated when the elasticity is not a sufficient statistic. Second, we discuss conceptually the key issues that arise in the empirical estimation of the elasticity of taxable income using the example of the 1993 top individual income tax rate increase in the United States to illustrate those issues. Third, we provide a critical discussion of selected empirical analyses of the elasticity of taxable income in light of the theoretical and empirical framework we laid out. Finally, we discuss avenues for future research.
Fodder to beat The Joker about the head with/showing the conservatives who cry bloody murder about returning the top marginal tax rate to (gasp!) 39% and change to be idiots.Following the supply-side debates of the early 1980s, much attention has been focused on the revenue-maximizing tax rate. The revenue maximizing tax rate τ∗ is such that the bracketed expression in equation (5) is exactly zero when τ = τ∗. Rearranging this equation, we obtain the following simple formula for the tax revenue maximizing rate τ∗ for the top bracket:
τ∗= 1/(1+a·e) (ref7)
A top tax rate above τ∗ is inefficient because decreasing the tax rate would both increase the utility of the affected taxpayers with income above z ̄ and increase government revenue, which could in principle be used to benefit other taxpayers.13 The optimal income taxation literature following Mirrlees (1971) shows that formula (7) is the optimal top tax rate if the social marginal utility of consumption decreases to zero when income is large (see Saez, 2001). At the tax rate τ∗, the marginal excess burden becomes infinite as raising more tax revenue becomes impossible. Using our previous example with e = 0.25 and a = 1.5, the revenue-maximizing tax rate τ∗ would be 72.7 percent, much higher than the current US top tax rate of 42.5 percent when combining all taxes. Keeping state income and sales taxes, and Medicare taxes constant, this would correspond to a top Federal individual income tax rate of 68.4 percent, very substantially higher than the current 35 percent but lower than the top Federal income tax rate prior to 1982.