テクニカルレポート

ディスカッション／ワーキング・ペーパー

text

Discussion Papers In Economics And Business. 2026, 25-09-Rev.2, p. 1-18

Linear Commodity Tax Reform and Optimal Commodity Taxes under Partial Separability

Nishimura, Yukihiro

Graduate School of Economics, The University of Osaka

英語

text

2026-01

https://www2.econ.osaka-u.ac.jp/econ_society/dp/2509R2.pdf

Revised : Commodity Taxes under Partial Separability Cannot Be Undistorted / Yukihiro Nishimura [25-09-Rev., 2026]

Under a regime of nonlinear income tax and fully linear commodity taxes, we may not be able to construct a welfare-improving tax reform towards uniform taxes on a subset of commodities. Furthermore, distortions of production that alter relative wages can improve welfare by influencing mimickers’ consumption choices and thus relaxing incentive compatibility constraints. We then identify conditions for optimal uniform taxation within separated consumption groups. Specifically, to neutralize heterogeneous cross-substitution effects across income classes, uniform commodity taxes require parallel income effects, so the restrictions on the Engel curves cannot be dispensed with even under nonlinear income taxation.

102581

Linear Commodity Tax Reform and Optimal Commodity Taxes under Partial Separability

Nishimura, Yukihiro

Graduate School of Economics, The University of Osaka

英語

2026-01

Discussion Papers In Economics And Business

25-09-Rev.2

1

18

https://hdl.handle.net/11094/102581

https://www2.econ.osaka-u.ac.jp/econ_society/dp/2509R2.pdf