Medallions for Everyone

The more I think about this Yglesias tweet the more I like it:

There should be a hard cap on the number of cars allowed in the city with tradeable permits.

Let the market decide the balance of private vehicles vs rides-for-hire.

Paint tons of bus lanes and let normal people ride electric scooters. https://t.co/NRBlEFhjJN

— Matthew Yglesias (@mattyglesias) July 25, 2018

What this basically amounts to is extending the medallion concept from taxis to all cars (and presumably trucks, but excluding municipal vehicles). And I like it! You pick a number of cars that is suitable to the city's car infrastructure and you sell that many medallions.

There are certainly potential problems. For one, you might question whether it makes sense to treat all cars equally. A taxi is used intensively—time spent off the street is wasted opportunity to earn money—which is good in some ways but bad in others. A medallion system is insensitive to where, when, and how often cars are on the roads. This is arguably not ideal if the goal is to keep cars off the streets.

You could also argue that a simple car tax would make more sense. Conceptually, this would be similar to medallions that expire every year. Or you could argue for a tax that varies by location and time of day, perhaps facilitated by GPS data. A car trip from a residence to the hospital in an outer borough doesn't cause nearly as much damage as a car trip through Manhattan during rush hour. Maybe congestion pricing, even a fairly blunt variety, would be preferable to a policy that punishes those trips equally.

I also wonder how you would treat motorcycles. On the one hand, they take up less space than cars, and they are more energy-efficient. On the other hand, they pollute more, and if they were given favorable regulatory status I imagine they would proliferate rapidly.

And what about e-bikes? Right now e-bikes and motorcycles are fairly distinct categories, but if you put regulatory pressure on that distinction, I would expect it to deform. Already I see motorcycles and motor scooters (the kind where you sit down, like a small motorcycle) in the bike lane fairly often.

So anyway there are issues, but it doesn't strike me as a crazy idea at all.

[minor edit to fix typo]