Optimal Income Tax
Simulator

Given an elasticity of taxable income, a Pareto parameter for the income distribution, and a social welfare weight, compute the revenue-maximising or welfare-maximising top marginal tax rate using the Saez (2001) formula.

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Empirical presets

Saez (2001); Chetty (2012)

Elasticity of Taxable Incomeε

Chetty (2012) meta-analysis: 0.1–0.5; central estimate 0.25

Pareto Parameter of Income Distributiona

US upper tail: ~1.5–2.5 (Saez 2001). Lower a = more concentrated top incomes.

Social Welfare Weight on Top Earnersg

0 = revenue-maximising (Laffer peak); 1 = equal welfare weights (utilitarian)

τ* = 69.6%
Revenue-Maximising · Laffer Peak

At these parameter values, a top marginal rate of 69.6% maximises tax revenue from incomes above the threshold. Raising the rate further would reduce revenue as high earners reduce taxable income.

0.25
ε
1.75
a
0.00
g

Shareable link: parameters encoded in URL hash

Revenue-maximising rate: τ* = 69.6%
020406080100Top marginal tax rate τ (%)0%35%70%105%τ* = 69.6%

Revenue normalised to 1 at τ*. Assumes Pareto-distributed top incomes with parameter a = 1.75.

Optimal top rate τ* across empirical ranges of ε and a (g = 0.00 fixed). Highlighted cell = current parameters.

ε \ aa = 1.5a = 1.75a = 2
ε = 0.187%85%83%
ε = 0.2573%70%67%
ε = 0.557%53%50%