The difference in wealth between typical households in each racial group ballooned to $236,500 in 2009, up from $85,000 in 1984, according to the study, released Wednesday. By 2009, the median net worth of white families was $265,000, while blacks had only $28,500.

Income gains are also a major differentiating factor, even when whites and blacks have similar wage increases. Whites are typically able to put more of their raises towards accumulating wealth because they’ve already built up a cash cushion. Blacks are more likely to use the money to cover emergencies.

Inheritances also make it easier for some families to build wealth. Among the families studied, whites were five times more likely to inherit money than blacks, and their typical inheritances were 10 times as big.

By Tami Luhby