In effect, Congress has decided to penalize marriage most at life stages when children benefit most from the commitment of more than one adult.

For young, low-income couples: Earn an additional $10,000, and it’s not uncommon to be left with half of that amount or less, even before counting the cost of items like commuting to work and childcare.

By contrast, when couples are past the normal child rearing age, Social Security is designed so that there are almost no marriage penalties and only marriage bonuses — in the range of $100,000 or more.

Eugene Steuerle