Unemployment rates are quite different for whites and blacks. Social networks may be the reason why:

But this stubborn fact remains: The African-American jobless rate is about twice that of whites, a disparity that has barely budged since the government began tracking the data in 1972. In last week’s jobs report, the black unemployment rate was 13.2 percent, while the white rate stood at 6.8 percent.

Discrimination has long been seen as the primary reason for this disparity, which is evident among workers from engineers to laborers. But fresh research has led scholars to conclude that African-Americans also suffer in the labor market from having weaker social networks than other groups.

Having friends and relatives who can introduce you to bosses or tell you about ripe opportunities has proved to be one of the most critical factors in getting work. Such connections can also help people hold on to their jobs, researchers say.

“It is surprising to many people how important job networks are to finding work,” said Deirdre Royster, a New York University sociologist. “The information they provide help people make a good first impression, get through screening and get hired.”

Considering sociologist Mark Granovetter’s oft-cited piece on how weak ties help people find jobs, perhaps this shouldn’t be too surprising. Social capital can go a long way toward accessing opportunities in society. Also, Royster’s book Race and the Invisible Hand is an interesting look at how this played out in one Baltimore vocational high school as faculty members tended to give white students access to their social networks while not giving the same privileges to black students.