By Liz Weston, NerdWallet My artist husband likes to say that if I were in charge of our spending, we’d be sitting on milk crates instead of furniture and that if he were in charge, we’d have no retirement accounts. The fact that we have both nice furniture and retirement funds is a testament to compromise — and the wealth-building power of marriage. Married people are significantly wealthier than single people in every age group, and the gap tends to widen as people approach retirement age.