This paper examines the market and welfare implications of potential Doha reform scenarios. The first part of the paper describes possible policy outcomes on the basis of existing WTO negotiations and positions—first in the agricultural sectors as identified by the so-called three pillars: market access, domestic support and export subsidies, second in non-agricultural market access (so-called NAMA), and finally the other components of the Doha negotiations. The second part of the paper provides a quantitative assessment—using the World Bank’s dynamic global general equilibrium trade model—of the first two components, i.e. the three agricultural pillars and non-agricultural market access, leaving aside the other (important) components for which a quantitative assessment is significantly more difficult. The analysis suggests that an ambitious Doha round would take the global economy some distance towards the maximum potential gain of global free trade—up to one-third. However, because of the binding overhang in tariffs, developing countries risk missing an opportunity to make more significant gains in income and exports.