This paper shows that the market structure of an economy's research sector is an important determinant of the aggregate growth rate, even though it has hereto been ignored in the new growth literature. To make this point in a concrete context, a simple model is used to show that import competition may stimulate growth by reducing the market power of domestic innovators. Specifically, import competition forces domestic innovators to chose between either quickening their pace of innovation or being displaced by foreign innovators. The pro-growth effect of import competition is shown to be welfare-increasing. The paper studies a number of policy implications including the growth effects of anti-trust policy, partial liberalization and trade in intellectual property rights.