Pré-publication, Document de travail: Our work contributes to the literature relating output structure and economic development by showing that growth gains from upgrading are not unconditional. Relying on data from a panel of Chinese cities, we show that the level of capabilities available to domestic _rms operating in ordinary trade is an important driver of economic growth. However, no direct gains emanate from the complexity of goods produced by either processing-trade activities or foreign _rms. This suggests that the sources of product upgrading matter, and that domestic embeddedness is key in order for capacity building and technology adoption to be growth enhancing.