We model a two sector economy with unionized labor markets and competitive product markets, where workers and unions care about their relative wages, and show that the presence of a relative wage concern could help generation a positive relationship between tax progressivity and wage pressure.

We study the empirical relationship between labor taxation and pretax wages in Italy. We find that higher tax progressivity increases pretax wages. To explain this result, we introduce in an informal way a relative wage effect and argue that the combination of this effect with the labor supply...

Atkinson and Stiglitz show that with weakly separability, differential commodity taxes are unnecessary given an optimal nonlinear income tax. Deaton showed that with an optimal linear progressive income tax, commodity taxes are superfluous under weakly separable and linear Engel curves. Using...