In economics, a stock of resources that may be employed in the production of goods and services. In classical economics it is one of the three factors of production, the others being labour and land.
Capital may be so broadly defined as to include all possible material, nonmaterial, and human inputs into a productive system, but it is usually more useful to confine the term to material assets in the hands of productive enterprises. In this sense, there are two forms of capital. Money or financial capital is a fluid, intangible form used for investment. Capital goods—i.e., real or physical capital—are tangible items such as buildings, machinery, and equipment produced and used in the production of other goods and services. Money capital is raised by selling stocks and bonds in order to finance the acquisition of real capital or capital goods. Capital goods are similar to savings because both require postponing current consumption to provide for future production and consumption.
In an accounting sense, the capital of a business firm is that part of the net worth that has not been produced by the operation of the enterprise, or, in other words, the original stock of net assets of the firm before any income is earned. The economist is more likely to speak of “real” assets, such as plant and equipment, factory and office buildings, and inventories of raw materials and of partly finished and finished goods, regardless of their financial status.
Economists of the classical school, beginning with Adam Smith, developed the earliest theory of capital, according to which capital arose out of the excess of production over consumption. The income earned by capital is profit, the counterpart to the wages and rent earned by the other factors of production. No thoroughly satisfactory theory of capital has been presented, and since the 19th century interest in developing such a theory has flagged.