<Li> Labor--human effort used in production which also includes technical and marketing expertise . The payment for someone else's labor and all income received from one's own labor is wages . Labor can also be classified as the physical and mental contribution of an employee to the production of the good (s). </Li> <Li> The capital stock--human - made goods which are used in the production of other goods . These include machinery, tools, and buildings . </Li> <P> The classical economists also employed the word "capital" in reference to money . Money, however, was not considered to be a factor of production in the sense of capital stock since it is not used to directly produce any good . The return to loaned money or to loaned stock was styled as interest while the return to the actual proprietor of capital stock (tools, etc .) was styled as profit . See also returns . </P> <P> Marx considered the "elementary factors of the labor - process" or "productive forces" to be: </P>

As a factor of production what is capital