Shows what happens when a specific social policy is tried out on an experimental basis prior to being enacted into law. By providing a trial of a variety of negative income tax plans carried out over a three-year period in four communities, the New Jersey-Pennsylvania Income Maintenance Experiment was designed to observe whether income maintenance would lead to reduced work effort on the part of those who received subsidies. This book evaluates the final project reportso n the experiment issued by Mathematica, Inc. and the Institute for Reasearch on Poverty at the University of Wisconsin. A Publication in the Continuities in Evaluation Research Series.