Fixed cab fares are a response to passengers' effective inability to negotiate cab fares. In general, while transport regulations benefit the incumbents to some degree by raising the barrier to entry (rather shockingly in the case of NYC taxi medallions), they are generally supported by the public for reasons of safety.

There hasn't actually been a "broad increase in crime over the past fifty years" in the US; consider http://www.disastercenter.com/crime/nccrimn.htm which shows that, in North Carolina, violent crime in general has nearly doubled over that time, and robbery has increased by a factor of six, but murder rates have halved. A similar trend is seen in San Diego http://www.sandiego.gov/police/stats/ — violent crime has quadrupled, robbery has barely doubled, and murder has halved. Furthermore, these overall trends have been far from monotonic; the crime peak in 1990–1992 is far worse than anything we've seen over the last 20 years.

And there are lots of countries where low-tech hitchhiking is very much alive, and crime is much higher in most of them than in the US.

I think the real reason for the change is economic: as people in the US got much richer, they preferred the safety of private cars, airplanes, and other public transport, to the cost savings of hitchhiking.

Regardless, that's a problem of information. You want to know if the person you're riding with has a record of trying to rob or rape previous drivers or passengers, or even leering at their tits.

"The empty seat problem in private cars is more of an issue with personal safety and the broad increase in crime over the past fifty years."

It's more of an issue of the American perception of danger, and the anti-hitchhiking laws passed as a result. Lots of people still hitchhike all across the US.

I'd say that the danger in picking up a random stranger as a passenger isn't really about the danger that they're going to try to kill you. There's any number of other ways it can go wrong. They can smell bad. They can talk loudly or offensively. They can start going off with their theory about how the Jews run the country through the freemasons. They can be drunk and throw up. They can wind down the window and scream obscenities at nearby women. They can... well, ask any taxi driver for stories about what the worst things random strangers can do to your car.

If I were going to pick up random strangers to disrupt my otherwise-peaceful me-time alone in my car, it'd have to have a big incentive, and being able to split the money I pay for gas just ain't it. Being a taxi driver is a sucky job, and I don't wanna do it in my spare time for cents per mile.

Hmm, you have a good point — aside from people in the US being paranoid about crime, they're also unbelievably intolerant, to the point that they're not comfortable around teenagers talking loudly, drunk people, or people with different political views.

I'm not sure you're in a position to be lecturing others about tolerance after a comment like that.

"Tolerance" is a noble concept in some sense. It means I respect the right of others to be stupid and annoying in the abstract, not necessarily in my passenger seat.

I'm a US citizen, and I don't claim to be an exception to our general lack of tolerance; I mean, I've been unreasonably annoyed at teenagers talking loudly, or people dropping cigarettes on the sidewalk, or making racist remarks, just like most people from the US. I'm just observing a fact.

As for "noble concepts", well, there's the kind of tolerance that's a "noble concept", and then there's the kind of tolerance that's an actual description of how some people behave toward other people, some of the time. Like, how Argentinians behave toward children, that people from the US don't. Or, for that matter, how Argentinians behave toward US tourists.

Turns out that there are real benefits to turning down your annoyance and smarter-than-thou attitude and digging folks who don't shop at the same supermarket you do. I can't always do it, but I'm glad when I can.

(By the way, when you complain about how awful it is to have to talk to someone who's stupid, you should consider how that would sound to someone who's a lot smarter than you are.)

Well that's great, but are we still talking about how folks don't want random strangers riding in their cars? Because I still don't want random strangers riding in my car, and I don't reckon that's in any way unreasonable.

I never said people from the US were unreasonable, just unbelievably intolerant. That's a matter of preference, and I don't think it makes sense to describe preferences as reasonable or unreasonable. It's like saying that it's unreasonable to have the flu or be short. Preferences aren't voluntary choices.