What I found …
- In 1994 Florida started a study of hard-limited welfare benefits. Clients were randomly sorted into one of two groups: a control group that got benefits similar to the old AFDC system and a group that got time-limited benefits as in the 1996 PRWORA system.
- In 1996 the Clinton administration passed the PRWORA welfare reform bill including time-limited benefits
- In 1999 the Florida study wrapped up
And this is now the law of the land, though I have heard that some changes made under Obama have softened the cruelty of the law.
Both William and Hillary Clinton tout PRWORA as an achievement, and I have not heard of remorse on their part.
Economist Robert Waldmann is the main blogging voice on this subject, with a series of articles titled "Welfare Reform Kills:" 1, 2, 3.