Not that kind of rivalry, but the kind spoken of in economics. GMU economist Bryan Caplan has a fascinating blog post in which he examines how rivalrous a married couple’s consumption bundle typically is with some aid from equivalence scales. Caplan takes an imaginary couple with the high earner making $60,000 and the low earner making $40,000 annually. Using four distinct empirical strategies,1 he finds that “the low-earning spouse makes out like a bandit. The surprise: The high-earning spouse gains as well – for all four ways to estimate real-world rivalry…[I]f one partner outearns the other by 50%, share-and-share-alike marriage raises the high-earner’s effective consumption by about 30%, and the low-earner’s effective consumption by about 100%. To quote Keanu, “Woh.””2
He concludes,
These calculations deliberately ignore all the evidence that marriage makes family income go up via the large male marriage premium minus the small female marriage penalty. So the true effect of marriage on economic well-being is probably even more massive than mere arithmetic suggests. Why then are economists – not to mention poverty activists – so apathetic?
See the full post for the calculations.