(CNN) The number of married women earning more money than their husbands has grown. But you won't hear them boasting about it.

A new study finds that many spouses would prefer to keep that fact on the down-low. Researchers analyzed Census Bureau data and discovered that in heterosexual marriages where the wife out-earns her husband, both spouses misreport in census surveys how much they actually make.

In these cases, both spouses tend to exaggerate the husband's income while deflating the wife's earnings.

2.9% How much husbands inflate their incomes in surveys when their wives out-earn them

The study, co-authored by Marta Murray-Close and Misty Heggeness, found that husbands who earn less than their wives reported their income to be 2.9% higher than what was on their tax returns. However, researchers found that wives inflated their husband's earnings even more than the husband did.

When it comes to reporting the wife's income, the opposite was true.

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