What determines how much the owners of land and capital earn for their contribution to the production process? Before answering this question. we need to distinguish between two prices: the purchase price and the rental price. The purchase price of land or capital is the price a person pays to own that factor of production indefinitely. The rental price is the price a person pays to use that factor for a limited period of time. It is important to keep this distinction in mind because, as we will see, these prices are determined by somewhat different economic forces.

Having defined these terms, we can now apply the theory of factor demand that we developed for the labor market to the markets for land and capital. The wage is, after all, simply the rental price of labor. Therefore, much of what we have learned about wage determination applies also to the rental prices of land and capital. As Figure 7 illustrates, the rental price of land, shown in panel (a), and the rental price of capital, shown in panel (b), are determined by supply and demand. Moreover, the demand for land and capital IS determined just like the demand for labor. That is, when our apple-producing firm is deciding how much land and how many ladders to rent, it follows the same logic as when deciding how many workers to hire. For both land and capital, the firm increases the quantity hired until the value of the factor’s marginal product equals the factor’s price. Thus, the demand curve for each factor reflects the marginal productivity of that factor.

We can now explain how much income goes to labor, how much goes to landowners, and how much goes to the owners of capital. As long as the firms using the factors of production are competitive and profit-maximizing, each factor’s rental price must equal the value of the marginal product for that factor.Capital each earn the value of their marginal contribution to the production process.