Thomas Malthus' 200-year-old argument that people are poor because they lack self-discipline continues to frame U.S. welfare policy despite substantial evidence to the contrary, say two sociologists in the latest issue of American Sociological Review.

In their article covering the 200 years of welfare debate, Fred Block of UC Davis and Margaret Somers of the University of Michigan say Malthus, a founder of classical political economy and modern population theory, used a hidden narrative in his argument about poverty, perverse incentives and population growth that continues to convince policy-makers today.

"Malthus effectively redefined the understanding of poverty from a problem of inadequate income to a problem of bad behavior by welfare recipients," they write. "Once poverty is understood as the result of bad behavior, then it is obvious that government policies should focus not on giving the poor money but on changing their behavior."

Somers and Block say that neither perversity of the welfare system nor bad behavior by the poor is the primary cause of poverty.

"So it is no surprise," they write, "that after almost a decade of trying to change the behavior of the poor, poverty rates in the United States are still rising."

U.S. welfare policy, starting with legislation passing in 1996, has been shaped by the assumption that that welfare recipients can pull themselves out of poverty just by exercising self-discipline and working hard, according to Block and Somers.

The two sociologists point out that since the federal minimum wage has not increased since 1997, while urban housing costs have risen steeply, poverty has intensified for many working poor, particularly for single parents.