"You have many, many politically independent suburbs that use exclusionary zoning to create housing only for families with higher incomes. As families with wealth move further and further out of urban areas you develop these very high-poverty neighborhoods where the schools begin to fail, you have high crime and low wages,” Jargowsky said.

Exclusionary zoning is when a suburban district sets a housing requirement that implicitly excludes lower-income families, like setting a minimum square footage of 3,000 feet. Families that cannot afford to purchase a house that large are thus unable to become members of that community. And more affluent people are also migrating into suburban areas, exacerbating the sprawl that leaves poor families in isolated communities.

Paul Jargowsky, a professor of urban research and education at Rutgers University and one of the study analysts, said the migration of Americans toward poverty areas is primarily driven by two phenomena: exclusionary zoning and suburban sprawl.

That is a significant increase from the 2000 level of 45 million people or 18 percent of the population.

The report, based on data from the 2000 Census and figures collected from the American Community Survey from 2008-2012, revealed that in 2012 about 77 million people, roughly 25.7 percent of the U.S. population, lived in a poverty area — where more than one-fifth of residents earn an income below the poverty line of approximately $23,600 a year for a family of four.

Exclusionary neighborhood zoning and suburban sprawl have led to an increase in the number of concentrated poverty areas, particularly in the South, according to an analysis of a recent U.S. Census Bureau report released Monday.

The population increase in poverty areas is especially pronounced in southern states. While the South has long been home to some of the nation’s poorest families, the percentage of people living in poverty areas in the region increased 10.6 percent in the years studied, from 46.7 percent in 2000 to 57.3 percent in 2012.

Collectively, all the states in the South account for more than 34 million people living in poverty.

The general poverty rate increased the most in Tennessee (up 26 percent), North Carolina, (17.9), Oregon (16) and Arkansas (15.7). It decreased the most in Washington, D.C. (down 6.7 percent), Louisiana (3.6) and West Virginia (2.3).

The national poverty rate stands at 14.9 percent, according to the 2010 Census data, the most recent available.

In addition to the growing number of poverty areas, suburban sprawl has reshaped the landscape of major U.S. cities including Atlanta, Charlotte, North Carolina, and Dallas.

While higher poverty rates in the South are a result of long-standing socioeconomic inequality, Jargowsky said, the increasing sprawl into suburban areas mostly populated by higher-income families has also led to a significant increase in segregated neighborhoods.

As more affluent suburban neighborhoods are created, the poor become more and more isolated, and opportunities to build affordable housing dwindle because the additional land is used for larger, more expensive homes.

"You have suburban sprawl combined with legally enforced economic segregation, and that’s public policy," Jargowsky said.

Alemayehu Bishaw, author of the report, said in a news release that living in a high-poverty area makes it much harder for low-income families to improve their prospects.

"Researchers have found that living in poor neighborhoods adds burdens to low-income families, such as poor housing conditions and fewer job opportunities," the release read.

African-Americans were the most likely to live in concentrated areas of poverty, at 50.4 percent, followed closely by American Indians and Alaska Natives at 47.8 and 48.3 percent, respectively.

The percentage of white people living in high-poverty areas also shot up, from 11.3 percent to 20.3 percent in the years studied, indicating that the problem is affecting Americans across the board.

"It’s like having a double burden of poverty in income and in your neighborhood," Jargowsky said.