This paper investigates the dynamic effects of international trade on technical progress and economic growth using an endogenous growth model where learning by doing, though bounded in each good, exhibits spillovers across goods. The study examines two economies: an LDC (less technologically advanced) and a DC (more technologically advanced). Under autarky, the LDC experiences a growth rate and technical progress rate that are less than or equal to those under free trade, while the DC experiences rates that are greater than or equal to those under autarky. Unless the LDC's population is significantly larger and the initial technical gap is small, the LDC will not be able to catch up with the DC. Therefore, the LDC experiences dynamic losses from trade in terms of technical progress and growth, while the DC experiences dynamic gains. However, the LDC consumers may benefit from higher intertemporal utility due to improved welfare from technical progress abroad. For the DC, as long as they are not overtaken by the LDC, they will enjoy both rapid technical progress and traditional static gains from trade, leading to an unambiguous improvement in intertemporal welfare. The paper also discusses the theoretical and empirical literature on the effects of trade on growth and technical progress, highlighting the importance of distinguishing between growth and level effects.This paper investigates the dynamic effects of international trade on technical progress and economic growth using an endogenous growth model where learning by doing, though bounded in each good, exhibits spillovers across goods. The study examines two economies: an LDC (less technologically advanced) and a DC (more technologically advanced). Under autarky, the LDC experiences a growth rate and technical progress rate that are less than or equal to those under free trade, while the DC experiences rates that are greater than or equal to those under autarky. Unless the LDC's population is significantly larger and the initial technical gap is small, the LDC will not be able to catch up with the DC. Therefore, the LDC experiences dynamic losses from trade in terms of technical progress and growth, while the DC experiences dynamic gains. However, the LDC consumers may benefit from higher intertemporal utility due to improved welfare from technical progress abroad. For the DC, as long as they are not overtaken by the LDC, they will enjoy both rapid technical progress and traditional static gains from trade, leading to an unambiguous improvement in intertemporal welfare. The paper also discusses the theoretical and empirical literature on the effects of trade on growth and technical progress, highlighting the importance of distinguishing between growth and level effects.