This paper explores the quantitative effects of trade liberalization envisioned in a transatlantic trade and investment partnership (TTIP) between the United States and the European Union. We use a quantitative trade model that, in contrast to other works, features consumptive and productive uses of land and we allow for labor mobility and a spatial equilibrium. Our calibration draws mainly on the world input–output database (WIOD). The eventual outcome of the negotiations is uncertain. Tariffs in E.U.–U.S. trade are already very low, however, so that an agreement will have a major impact only by eliminating nontariff barriers. These are extremely hard to quantify. We address these uncertainties by considering a corridor of trade‐liberalization paths and by providing numerous robustness checks. Even with ambitious liberalization, real income gains within a TTIP are in the range of up to 0.46 percent for most countries. The effect on outside countries is typically negative, yet even smaller. Taking land into account scales down the welfare effects strongly. Interestingly, we find that all German counties derive unambiguous welfare gains even though the model allows for negative terms‐of‐trade effects. Our analysis also implies that in order to arrive at the same welfare gains as under a TTIP, a multilateral liberalization would have to be much more ambitious for the U.S. than for the E.U.