"Once-off" and Continuing Gains from Trade
用动态李嘉图模型分解贸易收益为一次性收益和持续性收益，发现两种收益的大小与国家规模、生产结构相似性、时间偏好率和研发生产率有关。
Most economists are familiar with the static or "once-off" welfare gains created by opening an economy to trade. Much less is known about how the resource reallocations necessitated by this move affect long-run growth, and hence whether they provide dynamic or continuing welfare gains in future periods. This paper employs a dynamic Ricardian trade model to provide a decomposition of the gains from trade into "once-off" and continuing categories. In one version of the model, trade is always welfare enhancing; in the other, "once-off" losses may occur alongside dynamic gains. In both versions the magnitude of "once-off" and continuing effects are related to absolute and relative country size, similarity in production structures, rates of time preference, and the productivity of R&D.