Models of the labor supply behavior of single persons predict that a negative income tax (NIT) will always reduce the labor supply and
earnings of such persons. I consider three models of family labor supply; and find that in all three, a NIT might raise a given family
member's labor supply and might also raise total family labor supply:
in one, a NIT could even raise total family earnings. These models
and recent empirical estimates (showing positive NIT effects on some
family members¿ labor amply and on some families¿ earnings) suggest
that the work disincentive effects and the cost of a NIT may be less
than has previously been thought