Want to know how to ensure your wife or girlfriend’s satisfaction with her Valentine’s Day present? Over breakfast, casually mention that recent census data shows women outnumber men in your area, and that men are apparently a scarce commodity (or maybe just the first part).

Why would this matter? Well, according to a recent study from the University of Minnesota, perceived gender ratio affects economic behavior in both men and women. Regarding your sweetheart’s present, after female participants read an article describing a dearth of men in the local population, the amount of money they expected a man to spend on dinner, Valentine’s Day, and engagement rings decreased (and likewise, they expected men to woo them more lavishly when there were reportedly more men than women).

This sort of news had a complementary effect on men. When male participants read an article indicating an excess of men in the population and then answered questions about monthly spending habits, they reported they would borrow 84% money more and save 42% less. When the article reversed the ratio, men accordingly borrowed less and saved more. (Unlike men, women’s spending habits were not altered by the reported population inequality, only their expectations were.)

Moreover, an apparent discrepancy in gender was all it took to increase men’s willingness to make financially riskier decisions. In another experiment, participants were shown photos of groups of people: some where women outnumbered men, some where men outnumbered women, and some with an equal number of each. Afterwards, experimenters asked participants whether they would rather be paid the following day, or wait for a greater amount in a month. The result? After viewing photographs graced by fewer women, men were much more likely to choose $20 the next day over waiting a few weeks for $30.

As it turns out, researchers discovered that these results are born out in real populations too: In Columbus, Georgia, there are 1.18 single men for every single woman, and the average consumer debt is $3,479 higher than it is 100 miles away in Macon, where there are 0.78 single men for every woman.

So for those of you who are single and looking to find a match, here’s a little help from the US Census Bureau. Ladies, you’ll want to try your luck in the blue areas; guys, your best bet is in the red.

Oh, and Happy Valentine’s Day.