some Googling shows that in fact there has been a lot of attention paid to the question of the law's effects.
choosing for sources we'd find credible, here's a pro and a con:
http://www.prospect.org/print-friendly/print/V13/13/jencks-c.html
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On balance, welfare reform has turned out far better than most liberals expected. Most Americans now see it as one of the great successes of the 1990s. Instead of remaining wedded to the idea that PRWORA was a bad idea because it was a supported by the lunatic right, liberals need to rethink. My own conclusions are three:
Telling prospective parents that they would have to take primary responsibility for supporting themselves and their children was a good idea, because 60 years of experience showed that no other approach to reducing family poverty could win broad political support in America.
Shifting government largesse toward those who work was a good idea, because it helped erase the stigma of single motherhood and made more resources available to single mothers and their children.
Turning welfare over to the states was a really good idea, because most states currently take a less ideological view of single mothers' problems than does Congress.
http://www.wsws.org/articles/2000/jan2000/pov-j12.shtml
Mounting evidence of deepening poverty in the US reveals that the welfare reform policy adopted by the Clinton administration and the Republican Congress is devastating millions of US families. A December 1999 report entitled Recent Changes in the Impact of the Safety Net on Child Poverty found sharp increases in extreme poverty on the one hand, and little, if any, improvement in overall conditions for the majority of children in low-income families.
Kathryn Porter and Wendell Primus, the authors of the report, are researchers at the Center on Budget and Policy Priorities (CBPP), a Washington think tank. Their research found that poverty trends, which had been documented using initial post-welfare reform data, continued into 1998. Using previously unpublished statistics on child poverty for 1998, which were compiled by the US Census Bureau, their report concentrates on demonstrating the impact of welfare reform on children. While the Clinton administration continues to insist that “welfare reform is working,” many studies have reported increased hunger and homelessness among families with children.
The Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA) was passed by the US Congress and signed by Clinton in 1996. Temporary Assistance for Needy Families (TANF) replaced Aid to Families with Dependent Children, the decades-old safety net for families with children. This act also contained some of the most vindictive measures aimed at the poor since the first federal assistance programs were adopted during the Great Depression of the 1930s. Among other things, it set a five-year lifetime limit for cash assistance and gave the states power to adopt stringent restrictions in several other areas.
The CBPP study found that the welfare cuts had nearly offset any gains from the "longest peacetime economic recovery in US history." Employment and earnings among low-income parents have increased, but benefits have been sharply cut. The result is that while “the number of children living in poverty has declined significantly since 1993,” after 1995 the pace of decline dropped dramatically. “Measured on an annual basis, the number of poor children declined at a rate of 1.2 million per year between 1993 and 1995 and at a rate of 400,000 a year—one-third as much—between 1995 and 1998.”
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