An endogenous growth model in which two forms of capital good, physical capital and human capital, are produced in different sectors. In a standard set-up with a Cobb–Douglas production function in each sector the two production activities each exhibit constant returns to scale in the quantities of the two capital inputs. Hence, the model displays endogenous steady-state growth, where per capita consumption, output, the stock of physical capital, and the stock of human capital all grow at the same constant rate.