We examine the impact of policy uncertainty on trade, prices, and real income through firm entry investments in general equilibrium. We estimate and quantify the impact of trade policy on China’s export boom to the United States following its 2001 WTO accession. We find the accession reduced the US threat of a trade war, which can account for over one-third of that export growth in the period 2000– 2005. Reduced policy uncertainty lowered US prices and increased its consumers’ income by the equivalent of a 13-percentage-point permanent tariff decrease.