Abstract
Once upon a time, students of American politics believed that policy turned out as intended. But they have recently concluded that intentions are an inconsistent guide to results. Scrutiny of the effects of policy has increased: government agencies study the effects of welfare payments on work habits and income, of school reform on students' academic performance, and of environmental regulation on air and water quality. Social scientists scrap about such issues, and their work is followed fitfully by government and the press. These new concerns have altered the content of newspapers, the management of social agencies and the methods of social research. Even the character of public-service training programs in universities has changed.





