system
Given the following post, respond as if you're commenting on Reddit:
human
Why does the free market not work for public services?

In the UK, rail services are privately owned, which in theory should mean that there’s competition between rail firms, and in turn lower prices. However this isn’t the case at all, and rail fares are extortionate. My question is why? If it helps, I’m not sure if there’s any monopolies in place, which I imagine would give a good explanation. Just generally, I’ve heard that the free market works up until public services, at which point it falls apart. Is this the case would you say?
gpt
Public goods are generally underprovided by the market, which is probably what you're thinking of, but rail is not a public good.

Public goods are nonrivalrous (one person's consumption of the good does not prevent others from consuming it) and nonexcludable (there is no way to stop people from consuming the good). Rail meets neither of these criteria.