A model is developed in which two complementary forms of investment contribute to growth--- technology and skill acquisition, and growth takes two forms---TFP and variety growth. The rate of TFP growth depends more heavily on the parameters governing skill accumulation, while variety growth depends, roughly, on the difference between the parameters governing technology and skill accumulation. Conditions for the existence of a BGP are established, and the effects of various parameters are characterized. In an example, subsidies to skill acquisition (technology acquisition) are powerful tools for stimulating TFP growth (variety growth). Investment incentives off the BGP are also explored.