WASHINGTON -- For more than a decade, Chicago-based Ariel Investments has examined the investing habits of African-Americans. The company has made it part of its mission to increase minority participation in the stock market and 401(k) plans so minority investors will have a secure retirement.

Now, Ariel Education Initiative, the company's nonprofit affiliate, and Hewitt Associates, a human resources consulting firm, have released what they describe as a groundbreaking study showing that minorities still aren't investing in corporate 401(k)s at the same rate as whites and Asians.

The two companies found after analyzing 401(k) information for nearly 3 million employees at 57 large, primarily Fortune 500 businesses, that regardless of age or income, African-American and Hispanic workers have lower participation rates and contribute less to their 401(k) plans than their white and Asian counterparts.

Specifically, 66 percent of African-American employees and 65 percent of Hispanic employees participate in their company's defined contribution plans, compared to 77 percent of white workers and 76 percent of Asian workers.

The study also showed that African-American and Hispanic workers had higher rates than white workers of borrowing from their retirement accounts. Asian workers were the least likely to take a loan against their 401(k) plans, with less than one in five doing so, the report found.

I don't doubt Ariel's commitment to investor education. But we've known for at least 10 years that minorities are not investing at the same rate as whites. The more pertinent question is: Why is there still a gap?

That's a question the study doesn't answer. Neither does the joint news release from the two companies, or most media reports.

In an interview, Mellody Hobson, president of Ariel Investments, said she believes minorities are investing less for five reasons:

-- They don't know enough about investing.

-- They have misinformation about investing in a 401(k) plan.

-- They have trust issues.

-- When they do invest, minorities choose more conservative options such as investing in real estate and insurance products.

-- They have less exposure to the stock market.

Every reason Hobson listed reflects on the investing acumen of minority investors. However, studies show many companies haven't done the best job of explaining investment options or providing advice to all of their 401(k) participants. Is it so hard to appreciate that many new investors would be leery of investing their money in the stock market, especially of late? And the numerous scandals in the investment community don't exactly engender trust among a group of people who have experienced institutional mistreatment for decades. Continued...