The scarce resources that are useful not so much for direct and immediate satisfaction of human wants as for producing other goods or services. Economists often find it useful for purposes of theoretical simplification to group the millions of different sorts of factors of production into several very broad categories and then discuss them as though all the items within each category were perfectly substitutable for each other and therefore traded on a single market. The simplest such conventional categorization of the factors of production divides them into land, labor, capital, and sometimes also entrepreneurship and/or human capital.

[See also: derived demand]