Though, I think a lot of people here think the takeaway is "if you're in a relationship and you do separate now, you'll be happier if you put them together" and NO NO NO that's not it at all.
It's "if y'all were already the type to put them together, you're probably happier than the types who didn't."
It sounds like they specifically attempted to avoid that reasoning by taking the decision away from the couples: "In a six-wave longitudinal experiment, we investigated whether randomly assigning engaged or newlywed couples to merge their money in a joint bank account increases relationship quality over time."
I would like to see more of this by income level, though, which isn't mentioned in the abstract. If you don't have much, and you have separate accounts, I certainly see how it results in more resentment, feeling that one of you is having to sacrifice or do more. That lines up with their findings of joint account promoting feelings of cohesiveness. If you are making more, it seems like it would be less of a significant factor in the relationship.
oh god, I just realized this study is based off self reporting isn't it? In other words couples are happier when they perceive they have a joint checking account with no separate accounts.
I think just seeing double the balance (or much more for high income disparity households) on bank statements due to being assigned to the joint-account cohort seems likely to make a lot of people feel more psychologically secure by itself, regardless of how their relationship is going.
They try to get at that causation problem with the random assignments: they randomly assigned the couples into three groups: no intervention, must do joint finances, and continue their separate finances (all 230 couples in the study started with separate finances). After two years the joint finance groups were happier in their relationship and less likely to have broken up.
So, if you had RTFM'd, you'd have seen that they are trying to get at causation by doing a randomized controlled trial, the gold-standard for proving causation.
As others have said, they did a randomized trial. "Whereas couples assigned to keep their money in separate accounts or to a no-intervention condition exhibited the normative decline in relationship quality across the first 2 years of marriage, couples assigned to merge money in a joint account sustained strong relationship quality throughout."
Sadly, I don't have access to the paper. May try and find a link to it later. I'm curious to know if they split the "no-intervention" cohort to look at the idea you are mentioning. That is, mayhap the cohort that got to do what they want was dominated by the separate accounts group? More strangely, it would be really weird if the no-intervention group saw an inverse result. That is, if given the choice and you keep joint accounts, you are unhappier than if you had kept separate.
> Procedure [of Study 1]: Once both partners completed the intake survey (month 0), we randomly assigned couples to one of three bank account structure conditions. We informed couples via e- mail and provided condition-specific instructions. In the Separate Condition, we instructed couples to continue using separate checking and savings accounts and to not open joint checking and savings accounts, for the duration of the 2-year experiment. In the Joint Condition, we instructed couples to open joint checking and/or savings account(s) (within 1 month of them receiving these instruc- tions), use those joint account(s), and discontinue using their separate account(s) for the duration of the 2-year experiment. In the No-Intervention Condition, we told couples that they could manage their money however they liked for the duration of the 2-year experiment.
This link is to a study that was a randomized trial, which means it can theoretically contribute to establishing causation:
> In a six-wave longitudinal experiment, we investigated whether randomly assigning engaged or newlywed couples to merge their money in a joint bank account increases relationship quality over time. Whereas couples assigned to keep their money in separate accounts or to a no-intervention condition exhibited the normative decline in relationship quality across the first 2 years of marriage, couples assigned to merge money in a joint account sustained strong relationship quality throughout.
No. The link is to an abstract of a study, and the abstract claims that it was a randomized trial.
A reasonable person may, of course, decide to trust the authors and assume they executed the randomization correctly. However, without being able to read the methodology of the study (which is paywalled), it is just that: an assumption.
This is a reasonable nitpick, but I'm responding to someone who said "correlation does not imply causation", which pretty clearly communicates that they didn't even read the abstract.
Note that I said it can theoretically contribute to causation—I'm not saying the study came to the correct conclusion, just that people should actually follow the link rather than critiquing the study based on the title alone.
Though, I think a lot of people here think the takeaway is "if you're in a relationship and you do separate now, you'll be happier if you put them together" and NO NO NO that's not it at all.
It's "if y'all were already the type to put them together, you're probably happier than the types who didn't."