Rich Americans spend their money differently than poor Americans—no great surprise there. But the differences in how families spend go beyond earnings. For instance, rich white families spend more on entertainment and groceries than rich black families. And black families at all income levels spend more on things that require a long-term contract, such as electricity and heating services, than white families at corresponding income levels.

These discrepancies illustrate an under-recognized aspect of racial inequality: Blacks don’t just tend to earn less than whites. Even when they earn as much, they seem to still have less access to goods and services than their white peers do.

That’s the finding of a paper by the sociologists Raphaël Charron-Chénier, Joshua J. Fink, and Lisa A. Keister of Duke University, who used data from the Consumer Expenditure Survey to assess the spending habits of white and black households in 2013 and 2014. They argue that access to credit, retail deserts, and discrimination could be major factors in why blacks spend less, in aggregate, than whites. Only one of these challenges—access to credit—is mitigated when black families earn more money.

When it comes to purchases that require a substantial sum of money up front, for instance a downpayment for a car or household appliance, lower-income black families were much less likely to make a purchase than their low-income white peers. That may point to inadequate credit access, a problem that plagues poor black households more frequently than poor white households. As income increases, that gap between blacks and whites narrowed, suggesting that higher-income black households were able to use income to overcome the credit barrier.