But a usable theory of economics needs tools for the analysis of the small as well as the large. When historians actually conducted research, they moved down from the level of aggregates to the behavior of individuals, and the analysis of discrete events. The macroeconomic theories that historians employed proved of little help when it came to the practical problems of an actual research agenda. The consequence has been a continual narrowing of the subjects that historians consider appropriate to economic analysis. The subculture of economic theory within history developed in large part without careful examination.
Most historians learn their conceptions of economics in history from each other.
The last generation of American historians to consciously incorporate economics into their work, the Progressives, taught at least two generations of historians many of their conceptions of economics. Social historians absorbed some economics by way of sociology. The institutional economists contributed some concepts. Post-war political theorists such as Louis Hartz contributed others. From the late 1960s to the present deliberate attempts have been made to incorporate economic theories drawn from Marx, Polanyi, and Gramsci.