I think this is driven by both culture and the grade of economic development of the country you live in. In my home country of Italy, it would be considered kinda crazy to charge your kids rent. There are very practical reasons behind it: high youth unemployment, low salaries when you're just starting your career. Rental apartments are also really expensive in big cities and you just can't afford one without getting a roommate (or a partner with a job). So people end up staying at home longer to save money for a down payment, and the parents are totally fine with it.

I live in the US now, and here, where it is (used to be?) easy to land a well-paying job fresh out of school, it is considered quite common to charge your children rent if they decide to stay at home. My feeling is that staying at home in the USA carries quite some stigma for both the kid and their parents. American culture puts a lot of value in self-reliance and financial independence, and the general idea is that you failed as a parent if your kids aren't able to afford their own place.

(I also have a feeling all of the above is changing dramatically, given the current cost of living crisis in America.)

Agreed. I think it's wild that such a position seems relatively common in the US (though at a surface level I understand that it's just a cultural difference).

The only situation in which I would consider charging my kids 'rent' is, if as adults, they were being irresponsible with their life, e.g. being a NEET and not helping out around the house. Even then I would hold the money in a separate account to gift back to them later.

I think it's parents' role to always be a source of almost unconditional comfort and security for their kids. Though I also think that this is unsustainable unless kids also do their best to maintain and respect that relationship.

I paid discounted rent to my parents once I had a job and still lived with them. Really not a whole lot. I think of it not as a payment for existing but as a contribution to the household and if I couldn't pay for some reason, they wouldn't have evicted me.

He's paying a fraction of market rate rent and has saved a lot of money.

He's eating food out of the communal pool and it's a running gag at local restaurants that he eats two entrees. I think it's fair that he contributes something, like he is working, except for this summer when he said "take this job and shove it" because he was working for a crew where the foreman was twice his age but didn't have any sense for construction. Instead, he's doing a lot of work around the farm to fix things up, some of which is stuff we need and some of which is stuff he wants.

He expects to inherit the farm, will probably move to our other house if and when he is ready to co-habitate as opposed to getting on the housing ladder in the conventional way.

In my house the >8 years old the kids start paying rent. They get paid for normal house work (minimum wage). Rent is ~$300/month. I pay the kid minimum wage for chores because that is work and work should be rewarded. They pay me rent. That rent and other expenses are ~80% of their pay. Some must go to savings and "taxes". They have to keep books as well. The rest is theirs.

I know other fathers that charge their adult children rent, keep the money, and then gift it to them at the wedding or to help them buy a house.

He comes and goes as he pleases but is usually pretty open about it. Also he has plenty of space to do construction projects he wants, he'd probably like to keep playing guitar past 11pm but there are limits!

Now it is not a good situation for sex for anyone involved but we have a lot of land so there's nothing better than a love nest made from glamping gear at least in the summer.