I’m not sure about likening marriage to a business relationship, but after being with my wife for more than half my life, and married for 20 years of it, I know that this article contains solid advice.

Someone once told me when I was teaching that equity is not equality. That’s something to bear in mind with many different kinds of relationships. There will be times where you have to shoulder a huge burden to keep things going; likewise there will be times when others have to shoulder one for you.

1. Bank on the partnership. In a corporate merger, there must be financial integration. The same goes for a marriage: Maintaining separate finances lowers the chances of success. Keeping money apart might seem sensible in order to avoid unnecessary disagreements, especially when both partners are established earners. But research shows that when couples pool their funds and learn to work together on saving and spending, they have higher relationship satisfaction and are less likely to split up. Even if you don’t start out this way and have to move gradually, financial integration should be your objective.

2. Forget 50–50. A merger—as opposed to a takeover—suggests a “50–50” relationship between the companies. But this is rarely the case, because the partner firms have different strengths and weaknesses. The same is true for relationship partners. I have heard older couples say that they plan to split responsibilities and financial obligations equally; this might sound good in theory, but it’s not a realistic aspiration. Worse, splitting things equally militates against one of the most important elements of love: generosity—a willingness to give more than your share in a spirit of abundance, because giving to someone you care for is pleasurable in itself. Researchers have found that men and women who show the highest generosity toward their partner are most likely to say that they’re “very happy” in their marriage.

Of course, generosity can’t be a one-way street. Even the most bountiful, free-giving spouse will come to resent someone who is a taker; a “100–0” marriage is surely even worse than the “50–50” one. The solution is to defy math: Make it 100–100.

3. Take a risk. A common insurance policy in merger marriages is the prenuptial agreement—a contract to protect one or both parties’ assets in the case of divorce. It’s a popular measure: The percentage of couples with a “prenup” has increased fivefold since 2010.

A prenup might sound like simple prudence, but it is worth considering the asymmetric economic power dynamic that it can wire into the marriage. As one divorce attorney noted in a 2012 interview, “a prenup is an important thing for the ‘monied’ future spouse if a marriage dissolves.” Some scholars have argued that this bodes ill for the partnership’s success, much as asymmetric economic power between two companies makes a merger difficult.

Source: Why the Most Successful Marriages Are Start-Ups, Not Mergers | The Atlantic