We are now in the midst of a notable revival of interest in the politics of the American states. During the last decade many studies have been conducted of the social, political and economic determinants of state policy outcomes. Several of these writers have argued that the relative wealth of a state, its degree of industrialization, and other measures of social and economic development are more important in explaining its level of expenditures than such political factors as the form of legislative apportionment, the amount of party competition, or the degree of voter participation. It has been claimed that such factors as the level of personal income or the size of the urban population are responsible both for the degree of participation and party competition in a state, and the nature of the system's policy outputs. By making this argument these writers have called into question the concepts of representation and theories of party and group conflict which, in one form or another, are the foundations for much of American political science.
There is a growing awareness, however, that levels of expenditure alone are not an adequate measure of public policy outcomes. Sharkansky has shown, for example, that levels of expenditure and levels of actual service are seldom correlated; presumably, some states are able to reach given service levels with much less expenditure than others.