SAM ROBERTS/The New York Times

The suburbs, which in 2000 accounted for 29 percent of the region?s poor people, a decade later were home to 33 percent of metropolitan New Yorkers living below the federal poverty level, according to an analysis of the latest census results.

The analysis, released on Monday by the Metropolitan Policy Program of the Brookings Institution, also found that while the number of poor people in New York City and Newark declined by 7 percent, or 120,000, the number in the suburbs rose by 14 percent, or 100,000, from 2000 to the census?s rolling 2008-10 American Community Survey.

The poor have typically been concentrated in big cities and rural America. Increasing poverty in the New York metropolitan area?s historically affluent suburbs mirrored a national trend detailed in the analysis, ?Confronting Suburban Poverty in America? by Elizabeth Kneebone, a fellow at the Metropolitan Policy Program, and Alan Berube, a deputy director of the program.

The first decade of the 21st century was a tipping point, the authors wrote. Suburbia, they said, is now home to the ?fastest-growing poor population in the country.?

While New York and Newark?s combined share of poor people in the region dipped from 71 percent to 67 percent, the cities were home to twice the 800,000 or so people who officially qualified as poor in the suburbs in 2010.

?It seems like as the city prospered and got more expensive over the 2000s, poverty crept up in a lot of the region?s older suburban communities,? Mr. Berube said.

?It might not have been people moving from city to suburban neighborhoods per se, but as the region creates more low-wage jobs, and attracts more new immigrants, low-income households that in the past might have located in the Bronx or Brooklyn are now settling in places like northern New Jersey and Westchester County.

?It?s telling that the city?s ?suburban? borough, Staten Island, is the only one that saw its poor population increase over the 2000s.?

Christopher Jones, vice president for research of the Regional Plan Association, blamed higher housing prices for the demographic shift.

The rising cost of shelter pushed poorer people out of Manhattan and Brooklyn, in particular.

Also, he said, a smaller percentage of workers from suburban areas like Nassau County were commuting to high-paying jobs in Manhattan, and the jobs that were in their hometowns were at shopping malls, in health care and in landscaping, and generally paid less.

At the same time, tenants were doubling up and living in illegal apartments.

Dozens of smaller cities, townships and boroughs registered double- and even triple-digit increases in their poverty rates over the decade.

Among the places where the population of poor residents increased since 2000 were, in New Jersey, Bayonne, Bergenfield, Clifton, Edison Township, Garfield, Hoboken, Hunterdon County, Lakewood, Linden, Mount Olive, New Brunswick, Passaic, Paterson, Perth Amboy, Raritan, Summit, Teaneck and Woodbridge; on Long Island, Brookhaven and Glen Cove; in Westchester, Ossining; in Putnam County, Carmel; and in Rockland County, Ramapo.

Poverty rates increased in some places even after the recession officially ended in 2009, according to the Brookings analysis, but the poor population declined from 2000 to 2010 by 11 percent in Brooklyn and by 10 percent in Manhattan.

It rose 18 percent on Staten Island.

According to federal guidelines, the current poverty level for a family of four is annual income below $23,350.