Integration a.ects economic growth mainly through two different channels : The scale-effect channel and the factor-reallocation channel. In order to investigate both channels within a unifying framework, we employ a simple descriptive growth model. The scale-effect channel increases either the long-run growth rate or the level of the balanced growth path. The factor-reallocation channel is ambiguous. It is shown under which conditions this mechanism induces either a rise or a fall in the long-run growth rate. In addition, a number of policy conclusions are drawn.