By Sheila R. Zedlewski Director, Income and Benefits Policy Center of the Urban Institute

The images of people trapped in New Orleans after Katrina have rekindled interest in American poverty.

New Orleans is a particularly poor city - its poverty rate is more than double the national average.

Katrina has raised concerns over America's social welfare system

One of every four New Orleans families lives below the federal poverty level ($19,000 annual cash income for a family of four in 2005), compared with about one in 10 nationally.

These same images also made it clear poverty hits some groups harder than others. Nine in 10 poor people living in New Orleans are black. Two-thirds are single mothers and their young children.

Why does poverty persist in an economy growing, on average, by 5% per year over the last decade?

Studies point to education deficits, single parenthood, and a steady influx of illegal immigrants. About one in five blacks and almost half of Hispanics in the United States lack a high school diploma - the typical ticket to a job.

Single parenthood - whether due to out-of-wedlock pregnancy, divorce or incarceration can impoverish the sole earner who's trying to foot all the bills and pay for child care besides.

Currently, government is concentrating more on the root causes of poverty - education deficits and single parenthood - than families' income deficits.

The Bush administration has launched initiatives to boost school performance and encourage low-income parents to marry.

At best, though, these are long-term solutions for an immediate problem - like diet and exercise for a patient in the throes of cardiac arrest. Meanwhile, poverty has increased in America every year since 2001.

Hand outs

In the meantime, what help is available?

Government safety-net programs offer up to $500 per month for a family of four for help with food purchases, and most poor children are eligible for government health benefits even though many of their parents aren't.

Louisiana's cash welfare programme pays $240 per month for the few families that qualify. Lucky families might also get housing assistance on a first-come, first-served basis, but there isn't enough to go around.

As for low-income workers, only about a third of unemployed Americans receive a cash "insurance" benefit equal to little more than one-third of their earnings for up to six months.

Some poor people will put down roots where Katrina blew them. But with limited skills and work experience, many will turn to their host cities' social services, often straining already overtaxed systems.

Those with jobs do better. Low-income working families can get a refundable tax credit of up to $4,000 per year. Some lucky working parents also get subsidised child care - again, it's first-come, first serve.

Katrina challenges this safety net. The poor of New Orleans do not have money in the bank, and few own insured homes.

All comers will get food stamps, and some Katrina victims will get government health benefits. The poor will need much more.

Katrina's legacy

Evacuated families have scattered throughout the United States.

Some poor people will put down roots where Katrina blew them. Some may even find jobs. But with limited skills and work experience, many will turn to their host cities' social services, often straining already overtaxed systems.

Many other poor people will try to head back home to New Orleans.

But first, the city must build affordable housing and connect families with jobs and other support.

Americans are generous in times of crisis, and our huge non-profit sector will come through. With sufficient government resources and some fresh thinking, New Orleans could become a place where even the poorest will find a better life.

We can even hope that the terrible storm's legacy will include plans and actions to confront poverty head on and create a system that protects all from shock and ruin.

The Urban Institute is an economic and social policy research organisation based in Washington