> To put it bluntly, the increased happiness of millions of children is worth a couple children's health, or even lives. I don't think that's an accurate refra

> To put it bluntly, the increased happiness of millions of children is worth a couple children's health, or even lives. I don't think that's an accurate reframing. The opportunity cost isn't just happiness (by making playgrounds boring, presumably) but also safety, and therefore lives, in other areas. When you hit diminishing returns trying to make playgrounds 100% safe, spending the same resources on e.g. road design will save more lives.