Alfred Marshall (1842-1924) was one of the most influential economists of his generation. His book, Principles of Political Economy (1890) brought together the theories of supply and demand, marginal utility and the costs of production[?] into a coherent whole. It was the dominant textbook in England for a long period.
... income of $51,332 versus $32,188 for females. The per capita income for the town is $25,466. 7.0% of the population and 4.6% of families are below the poverty line. ...