I suspect the broken window fallacy takes place, but in the other direction.  If a parent stays home and takes care of their children there is zero apparent economic activity, or less if the stay at home parent cooks.  No childcare, less eating out, no maid services etc. However, the stay at home parent is doing that work which benefits the family and is probably also doing a better job of it than low cost help.<p>PS: This also depends on how much the primary income is, how much time it takes, and how old the children are.  If a family with three young children is supplementing a 140k primary income with a full time job that pays less than 50k it’s probably of little net benefit.  If on the other hand it’s 40k and 40k and the children are in school it’s probably a significant net gain.  Time is also a factor; one of the better and more common setups for families with school age children is a teacher parent. They share the same breaks, and the added stability can be a huge help.