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A "toxic inequality" between the haves and have-nots is hurting the U.S., with one issue in particular affecting American households: a widening racial gap between white and black families, according to a new study from Brandeis University.

The so-called wealth gap between whites and blacks has tripled over a 25-year period, according to the report, which looked at the same set of families from 1984 to 2009. The study found that white families in 2009 had assets worth $236,500 more than the wealth of black families, up from a gap of $85,000 in 1984.

The study found "little evidence to support common perceptions about what underlies the ability to build wealth, including the notion that personal attributes and behavioral choices are key pieces of the equation."

The income gap between white and black families has been noted before, with the U.S. Census Bureau finding in 2010 that the median income of black households was $32,068, compared with $54,620 for non-Hispanic white households.

But the Brandeis study looked at the reasons for the growing wealth gap, and it concluded the inequality is largely due to home ownership, income, family inheritances and education.

Here's how these four factors play out:

Home ownership: Because of the greater likelihood for family assistance and inheritances to help with down payments, white families start acquiring homes eight years earlier on average than black families.

In the recession, borrowers of color were more likely than whites to lose their homes because they were "more likely to receive high-interest risky loan products," the study found.

Income: Income gains for whites had more of an impact on their wealth, with the study finding that every $1 increase in income over the 25-year period added $5.19 in wealth. For blacks, $1 only added 69 cents of wealth.

The reason? Discrimination in hiring, training, promotion and benefits have "made it much harder for African-Americans to save and build assets." As a result of fewer work benefits such as retirement plans, black families tend to use wealth to cover emergencies, while whites are able to save and invest, the study found.

Inheritance: Whites were five times more likely to inherit than black families, with whites also receiving 10 times more wealth than blacks when they did, the study found. 

Education: College completion gaps are growing, with fewer blacks finishing college because of financial strain that forces them to leave school. About 80% of black students graduate with debt, compared with 64% of white students. 

So what's the solution? Public policy can help close the racial wealth gap, such as ensuring fair housing and lending policies, the study suggests. This divide spells potential problems for the U.S. economy as a whole, the study's authors said.

"Our economy cannot sustain its growth in the face of this type of extreme wealth inequality," Thomas Shapiro, director of Brandeis' Institute on Assets and Social Policy and a principal author of the study, told BrandeisNOW.

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