Chicago’s suburbs have nearly as many poor people as the city does, a study published Thursday says.

The number of suburbanites living in poverty had grown to 629,564 by 2011, according to the study, a review of U.S. Census Bureau data by the Heartland Alliance, a nonprofit group that fights poverty. That’s up 95 percent from the 1990 figure, the study says. The increase was much faster than the 29 percent overall suburban population growth during the period.

The study compared Chicago to a region that spans DeKalb, DuPage, Grundy, Kane, Kendall, Lake, McHenry and Will counties as well as the suburban parts of Cook County. By 2011, the suburban region was home to 49.6 percent of Chicago-area impoverished residents. The city figure was 50.4 percent.

Jennifer Clary, a Heartland researcher who helped author the report, said the state of Illinois ought to combat poverty by “raising the minimum wage, which has not kept up with inflation, ensuring that all workers have access to employer-sponsored retirement savings through a statewide automatic IRA program, and ensuring adequate funding for human services and safety-net programs.”

Clary called the state’s pension liability a distraction from potentially “far more severe” budget pressures stemming from poverty, including crime, health care and lost tax revenue.

Heartland’s approach has met resistance from some lawmakers who believe that what can fix poverty is not government but, rather, a business-owning class with freedom to take risks and hire people.

Nationally, 1 in 3 poor people live in the suburbs, researchers say. Many of those places haven’t kept up with rising demand for social services, public transportation and schools.

The federal government defines the 2013 poverty line for a family of four as an annual income of $23,550.

Chip Mitchell is WBEZ’s West Side bureau reporter. Follow him on Twitter @ChipMitchell1 and @WBEZoutloud, and connect with him through Facebook and LinkedIn.