As a new-ish parent in a HCOL area, this actually makes sense to me. Before children, we needed two incomes just to afford a relatively modest but comfortable l

As a new-ish parent in a HCOL area, this actually makes sense to me. Before children, we needed two incomes just to afford a relatively modest but comfortable lifestyle (both STEM related jobs, but not anywhere near FAANG salaries). But childcare is expensive and there are not a lot of affordable resources to lean on when things go haywire, for example when the child is sick and needs to stay home from daycare (a week of short notice babysitting can cost as much as an entire month of daycare). It has been extremely stressful and everyone around us that seems to be making it work either makes a lot more money than us (and can pay for a lot more help) or have a lot more help from relatives (or both). In LCOL areas, single income households are more realistic. And retired grandparents and relatives are more likely to be able to afford the area and help out with childcare. So it is not really about "affording" the kids, it is really more about how much help you can get. Certainly food and diapers cost money, but it is a drop in the bucket compared to child care. EDIT: Also, in terms of number of kids, there are some subtle influences there as well. A couple on FAANG salaries can easily afford 4-5 kids in a HCOL area. But modern car seats are massive and to shuttle that many kids around you would need a large SUV. But driving one of those around in an urban-ish area is a nightmare. It is little things like this that push down the fertility rates in these areas. Big rural open settings are great places for popping out kids. Expensive, high cost, high density environments are not.