While I don’t have an actual answer of any kind, I’d argue that a relationship can have “positive externalities” on altruistic endeavours, e.g. by discussing EA ideas much more frequently than you otherwise would (depending on your circumstances), and, in case the other person is into EA as well, keeping each other motivated. I personally would assume that my long term engagement in EA would drop quite a bit were it not for my relationship. That’s certainly different for other people however, so this isn’t anything more than one random data point.
While I don’t have an actual answer of any kind, I’d argue that a relationship can have “positive externalities” on altruistic endeavours, e.g. by discussing EA ideas much more frequently than you otherwise would (depending on your circumstances), and, in case the other person is into EA as well, keeping each other motivated. I personally would assume that my long term engagement in EA would drop quite a bit were it not for my relationship. That’s certainly different for other people however, so this isn’t anything more than one random data point.