The public policy questions of today are extraordinarily complex. Consider, for example, the problem of the growing number of children in poverty. It is reasonable to argue that the growing number of children in poverty is related to the rise in the number of single, female-headed households. Yet it is not very likely that the rise in single, female-headed households is the only cause of the increase in child poverty. Rather, the increase in child poverty is a complicated function, not only of the rise in the number of single, female-headed households, but also of the work and marriage disincentives built into welfare programs, the lack of quality child care that restricts employment opportunities for parents, and many other factors. To understand the problems facing modern society, it is necessary to move beyond simple notions of bivariate associations to develop more-sophisticated theories of how such problems arise. Social scientists and policy makers hope that by understanding the causes of social and economic problems they will be in a better position to design policy remedies to reduce the incidence and/or the severity of these problems.

Theory and model building

The process used by policy analysts to test theories concerning the causes of social problems and the policies developed to address them typically involves several steps. the first step is to develop a theory that expresses how a particular variable, such as the increase in child poverty, is related to other variables. Theory development usually takes place in the context of an existing literature. Researchers are constantly trying to identify and remedy knowledge gaps in various areas of social policy. Sometimes researchers identify variables that they believe are important to consider but which have been omitted in prior studies. in other instances, they may develop better measures of variables than those previously available (perhaps by conducting their own survey), or they may specify different relationships between a given set of explanatory variables and a policy variable of . . .