In Sec. 1 of this compilation, Cogan includes new evidence on work disincentives of a negative income tax (NIT). In Sec. 2, Cogan replies to issues raised in critical reviews of this testimony and concluded that it is important to distinguish between participation in and eligibility for an NIT program. In Sec. 3, Hosek discusses participation in the AFDC-Unemployed Fathers program and concludes that extending the program to all states would not cause much increase in caseload or cost. In Sec. 4, Lyon testifies on factors involved in the welfare decision, from which he concludes that welfare dependency cannot be equated with a welfare class. He includes information on benefit levels and job opportunities, welfare and Medicaid, migration, and administration. Implications of design problems for interpreting data from NIT experiments are covered in Sec. 5 by Welch. Problems included are payments based on self-reported income, accounting procedures for computing benefits, and sample selection and estimation of effects.