According to the study, the reforms have hit poor single mothers the hardest - the very group that they were designed to help. Between 1993 and 1995, it says, the disposable income of the poorest 20 per cent rose by $1,036, only to fall by more than half that amount - $577 - between 1995 and 1997. It attributes the decline to cuts in allowances as single mothers take low-paying jobs and confusion about their eligibility for state health benefits and food stamps.
"In our view," said the head of the study, Wendell Primus, "welfare reform should not be pronounced a `success' until the outcome among these - the poorest families with children - is one of consistent income gains rather than income stagnation or losses."
The reforms were introduced in 1996 in response to widespread public concern about the rising cost of state welfare benefits and the number of single parents who appeared to live permanently on welfare. The new system, which couples incentives with penalties, provides job preparation and training for benefit recipients, but also sets a period beyond when assistance will cease, whether or not the recipient has found work.
In the past five years, welfare rolls have been cut by half -- from 14 million to 7 million -- across the US, with most of the increase dating from after the introduction of the changes, an achievement that has been hailed by Democrats and Republicans alike.
In recent months, however, doubts have crept into the US euphoria. Voluntary groups have reported increasing resort to charity - soup kitchens and food banks - by people who cannot afford to buy food and many local authorities have acknowledged that once a family has left their register, they usually have no record of what happens to them. In at least three states - North Carolina, Pennsylvania and New York - thousands of former benefit recipients were removed from state medical and food stamp programmes after they obtained jobs, contrary to the administration's policy that no one should be worse off in work than they were on benefits.
The questions that are starting to be asked about welfare reform - its goals and effects - coincide with evidence that Americans have become more sanguine about taxation and even about the role that government can play. For Ronald Reagan the promise of personal tax cuts was a sure fire election-winner. Now, Congressional Republicans who have returned to their constituencies during the summer recess are reportedly finding less appetite for across-the- board income tax cuts than they had expected.