Adam Ozimek:

The so-called sharing economy is upsetting a lot of apple carts. Services such as Uber for transportation and AirBnB for housing have many fans, of course, but entrenched incumbents in these industries like things the way they are, or were. And their complaints often fall on receptive ears.
 Case in point: Last week, Washington Post columnist Catherine Rampell voiced concern that car-sharing services Uber and Lyft, which have emerged to compete with conventional taxi fleets, will prove less beneficial for consumers than many claim. Specifically, Rampell worried that the current intense competition will prove temporary, and that in the end cities will simply be “trading in one monopoly—loathed Big Taxi—for another, less regulated one.”
 I believe this confuses the two types of monopolies: natural and legal.