Divorce and marriage play much bigger economic roles for black children than white children in the United States, according to a new study by two UC Davis economists.

Marianne Page and Ann Huff Stevens find that in the first two years following a divorce, family income among white children falls about 30 percent, while it falls by 53 percent among black children.

"This difference increases dramatically in the long run," Page and Stevens write. "Three or more years after the divorce, about a third of the loss in whites' household income is recouped, but the income of black families barely improves."

In fact, three or more years after the divorce, the black families' income remains 47 percent lower than if the parents had remained together.

Marriage appears to have even greater benefits for black children whose single mothers marry than for their white counterparts, according to the study.

Page and Stevens estimate that while the family income of white children rises by 45 percent when their single parent marries, the family income of black children rises by 81 percent with marriage.

One reason for the difference in improvement is that married black mothers are more likely to work than married white mothers. On the other hand, when divorce occurs, the probability of black mothers working does not change, while recently divorced white women have an 18 percent greater probability of working.

The study, published in the February 2005 issue of Demography, followed a nationally representative, longitudinal survey of Americans conducted by the University of Michigan's Institute for Social Research.