Couples who pool all of their money (compared to couples who keep all or some of their money separate) experience greater relationship satisfaction and are less likely to break up; the effect is particularly strong among couples with scarce resources

Gladstone, J. J., Garbinsky, E. N., & Mogilner, C. (2022). Pooling finances and relationship satisfaction. Journal of Personality and Social Psychology, Mar 2022. https://doi.org/10.1037/pspi0000388

When couples decide to share their lives, they are simultaneously faced with the decision of how (or whether) to pool their finances. Does the way in which couples keep their money affect happiness in their relationship? Drawing on Interdependence Theory, we demonstrate across six studies (N = 38,534)—including both primary and secondary data—that couples who pool all of their money (compared to couples who keep all or some of their money separate) experience greater relationship satisfaction and are less likely to break up. Though joining bank accounts can benefit all couples, the effect is particularly strong among couples with scarce financial resources (i.e., those with low household income or who report feeling financially distressed). These findings replicate using experimental, cross-sectional, and longitudinal data sets, as well as in both individualistic and collectivist cultures.