The negative income tax proposed by Milton Friedman represents one of the fundamental ideas of modern welfare policy. However, the academic literature has raised two difficulties with it, one challenging its purported work incentives and the other suggesting the possible superiority of work...

We estimate the trend in the transitory variance of male earnings in the U.S. using the Michigan Panel Study of Income Dynamics from 1970 to 2004. Using both an error components model as well as simpler but only approximate methods, we find that the transitory variance started to increase in the...