Economics developed with the development of capitalist economies. Its history can be usefully categorized
- Schoolmen and mercantilism (??-1776)
- Physiocrats
- classical economics (Petty-John Stuart Mill)
- Karl Marx and Marxists (1867-)
- German Historical School
- neoclassical economics (1870-
- Institutionalists, mainly American (Thorstein Veblen, Commons, Mitchell and followers; 1899-)
- John Maynard Keynes
- Keynsian economics, keynesian economics (1936-)
- Austrian School (1871-current)
- Post Keynesians (current)
Contemporary economists do not have an agreement on which schools to develop to usefully explain existing economies. Neoclassical economics is dominant in many American undergraduate textbooks. Some extremely important tools, such as game theory, econometrics, and linear programming, do not easily fall unambiguously into only one of the schools listed above.