A Comparison of the Labor Supply Findings from the Four Negative Income Tax Experiments

Between 1968 and 1982, the United States federal government sponsored four negative income tax experiments. This paper provides a set of consensus estimates of the labor supply responses to these experiments. It is found that despite the wide range of treatments and evaluation methodologies, the results are remarkably consistent. On average, husbands reduced labor supply by about the equivalent of two weeks of full-time employment. Wives and single female heads reduced labor supply by about the equivalent of three weeks of full-time employment. Youth reduced labor supply by about the equivalent of four weeks of full-time employment. Estimated income and substitution effects are quite similar to those obtained from nonexperimental studies.