Comment by xenocyon

You make reference to protecting mass transit as well as to the cost to consumers. These arguments make sense if there are zero externalities, but unfortunately there are: carbon footprint, both directly as well as second order effects from increased congestion, commercial exploitation of subsidized infrastructure, increased collision risk to cyclists and vulnerable road users, abuse of contract law by preventing independent rate setting and concealing negotiable information, artificially depressed prices fueled by venture capital in order to create a monopoly and capitalize later. These externalities are borne by society at large, so a pure "let the consumer decide" philosophy is not fully justified in this scenario. Some of these externalities apply to taxis as well, which is precisely why regulating and limiting taxis is good, though I think one could do a lot better than the medallion system.