The division of labor and the extent of the market

A firm’s degree of specialization is modeled as the number of different goods it produces. When a firm chooses its degree of specialization, it faces a tradeoff between the fixed cost and the marginal cost of production. A firm’s degree of specialization is shown to increase with the extent of the market. Meanwhile, the real wage rate, as a measure of the extent of the market, is endogenously determined in the model and is shown to increase with the division of labor.