Drawing on economic data from 2,000 American families who were interviewed every few years between 1984 and 2007, researchers have found that the wealth disparity between white and black households has more than quadrupled, regardless of income bracket.
In 1984, the average white family in the sample group held around $20,000 more in assets than the average black family, according to a study conducted by the Institute on Assets and Social Policy at Brandeis University. By 2007, the "racial wealth gap" had increased by $75,000.
Additionally, the study found that middle-income white families hold much more assets (stocks, bonds, business interests, real estate other than primary residence) than do high-income black families. A quarter century ago, higher income black households held more wealth than middle-class white families.
"As a long-term socio-economic trend, this is both shocking and disturbing," Tom Shapiro, IASP director and the study's coauthor, told ABCNews.com.
The IASP study also found that many black families hold more debt than assets and at least 25 percent of black families had no assets to turn to in times of economic hardship.
The fourfold increase in the wealth gap reflects a variety of public policies, such as tax cuts on investment income and inheritances, which benefit the wealthiest Americans, Shapiro said. Persistent discrimination in housing, credit and labor markets are also factors that likely played a role in the widening of the gap, he said.
"Our study shows a broken chain of achievement," Shapiro said. "Even when African Americans do everything right -- get an education and work hard at well-paying jobs -- they cannot achieve the wealth of their white peers."
Shapiro, the author of "The Hidden Cost of Being African American," said data for the study was obtained over the years by a separate team of researchers from The Panel Study of Income Dynamics at the University of Michigan.
Around 15 percent of the 2,000 focus families were black; the rest were white. Three income groups were designated; low, middle and high income, with the highest income households earning (in today's dollars) $70,000 and up. The low-income group earned less than $40,000.
At least two steps could be taken immediately to shrink the gap, said Victor Corral, program manager for the Closing the Racial Wealth Gap Initiative, part of the Oakland-based Insight Center for Community Economic Development, which co-released the study along with the IASP.
"The first thing would be passage of a strong and independent Consumer Financial Protection Agency," Corral said, referring to a measure that is part of wider financial reform legislation currently being debated in the Senate.
Corral said minorities have been unfairly targeted and exploited by banks, whether through adjustable rate mortgages and higher interest rates on credit cards.
Changes in the tax code, which Corral said disproportionately benefits the wealthiest Americans, also could be made to reduce the gap. For example, there are no federal tax credits for renters who aspire to be homeowners, which he said is unfairly discriminatory against blacks and other low-income Americans.
Also, many blacks work in jobs that do not offer retirement plans, another reason for the gap.
"There needs to be more access to 401(k) plans for blacks," Corral said.