Welfare impact of a bilateral trade agreement

We develop a general equilibrium model and derive sufficient conditions for a trade agreement to be welfare-enhancing for a country. Our sufficient conditions require that the unconditional mean of the real GDP of the domestic country be higher and the unconditional mean of the total real import of the domestic country from the countries outside the trading block be lower following the trade agreement. We apply the model on U.S.-Australia trade agreement. Our results meet the sufficient conditions. Therefore, we conclude that the U.S.-Australia trade agreement has helped enhancing U.S. welfare.