Genuinely wondering how anything beyond a 4:1 ratio is bad? My kids are in daycare in TX with well over a 4:1 ratio and seem like they are doing fine. What sorts of downsides are you referring to?
It greatly depends on age! Having six kids ranging from 1-12 is a lot different than having six infants, who will likely all explode at the exact same time.
Because it's hard to exactly define "daycares shouldn't have more kids than they can take care of" they institute fixed ratios.
