Each culture is a little different. What are you going to do with your kids when the parents are working is a problem? At what time do you trust them to stay home by themself?

Where I live they are dismissed on their own as young as 8, and so long as they have a safe way home then a couple hours alone isn't going to hurt. There are enough electronic distractions at home now that they won't turn to delinquency.

15 is bonkers. There should be no need to keep your teenager on-leash for that long.

In Soviet Union times in eighties in Belarus it was considered ok that a child could stay alone at home from age of 7 when they started a school. Some parents opted for after-school programs and some relied on grandmothers like it was for me but some of my schoolmates stayed at home alone for few hours until their mothers would be back from work (fathers typically worked longer and further away from home).

And from the age of 9 there was no after-school options at least in my school.

8-12 unless they have serious developmental issues. 15 is ridiculous

> At what time do you trust them to stay home by themself?

As a GenXer, ~12 (?):

* https://en.wikipedia.org/wiki/Latchkey_kid