Resumen: We estimate the effect of tariff reforms on market access from the Doha Round until the Great Recession. Gravity estimates yield significant effects of the variation in tariff structure. The change in the Mercantilist Trade Restrictiveness Index reveals that the change in tariff dispersion reflects a restrictive selection counteracting the effect of average tariff reductions. Restrictiveness is concentrated in East Asia and Pacific while, in Latin America and Caribbean, selection is expansive. We illustrate reforms in China, finding strong restrictive selection. Simulations highlight reforms with unchanged dispersion for their larger improvement in market access and a simultaneous improvement in welfare. Idioma: Inglés DOI: 10.1080/17487870.2017.1305902 Año: 2018 Publicado en: Journal of Economic Policy Reform 21, 1 (2018), 39-58 ISSN: 1748-7870 Factor impacto JCR: 2.051 (2018) Categ. JCR: DEVELOPMENT STUDIES rank: 13 / 41 = 0.317 (2018) - Q2 - T1 Categ. JCR: ECONOMICS rank: 95 / 363 = 0.262 (2018) - Q2 - T1 Factor impacto SCIMAGO: 0.73 - Economics, Econometrics and Finance (miscellaneous) (Q1) - Business and International Management (Q1)