"Much of the social history of the Western world over the past three decades has involved replacing what worked with what sounded good. In area after area - crime, education, housing, race relations - the situation has gotten worse after the bright new theories were put into operation. The amazing thing is that this history of failure and disaster has neither discouraged the social engineers nor discredited them."
Exhibit A: From personal experience over the last two years in Washington, D.C. I have found that taxis in the city are cheap and ubiquitous, you can often get a cab within seconds, the drivers are usually friendly and helpful, and the fares are frequently run less than $10. From a consumers' standpoint, I don't know of any other city in America where taxis are cheaper and more available.
And yet it now looks like the D.C. City Council wants to engage in the practice that Sowell describes by replacing what is working with something that sounds good - restricting the supply of taxis by selling taxi medallions.