David Friedman on Taxis and Tipping

"This indicates to Friedman that most people in reality don't get carried away with the economic benefits of free riding and neglect public goods when a developed social rule dictates that we should to the right thing."

Doherty seems to say here that tipping is "the right thing" independent of a social rule. Why is it the right thing to do?

Tipping a cab driver is not a reward for personal service (which would be a private good). It is payment for the services of vacant cabs, which is a public good. More vacant cabs mean a shorter waiting time to hail a cab, which is a public good. Lindahl prices of vacant cabs (tips) can induce efficient entry in to the taxi industry. David Freidman is right to call tipping a cab driver an example of self-imposed, voluntary, Lindahl pricing of a public good.

What is "efficient entry" in an industry that is as regulated as the taxi industry? In New York you have to buy a medallion, which costs a lot of money. Entry is also far from free in other places, San Francisco, for example.

The IRS agent hanging outside my house is a taxi driver?

I tip my cab drivers just because that meant I didn't have to walk...