The Duchess of Windsor, who quipped, “You can never be too rich or too thin,” appears to have had it at least half right. New research by University of Michigan economists Betsey Stevenson and Justin Wolfers found that for rich and poor alike, as income climbs, so does one’s sense of well-being.

Their findings, to be published in the May 2013 American Economic Review, Papers and Proceedings, counter the idea that once certain basic needs are met, a rising income doesn’t translate into commensurate surges in happiness. That 1970s-era notion, named for economist Richard Easterlin and known as the Easterlin Paradox, holds that higher average income doesn’t translate into greater average happiness. Stevenson and Wolfers noted that other researchers — but not Mr. Easterlin — tweaked the paradox to say that it holds after a certain threshold income level — to take care of one’s basic needs — is met.