How many yellow taxi medallions exist in New York City?

How to get close to this number

This is a licence cap, so the answer is a fixed administrative number rather than a market outcome. The London black cab question on this site shows the same pattern: when a count barely moves for decades, look for a regulator setting it.

The date is the remarkable part: the cap has barely changed since 1937. A city that has grown enormously since then has the same number of licensed cabs, which is why the licences became tradeable assets worth more than the vehicles attached to them.

The price collapse is the economics lesson. Medallions traded above a million dollars when they were the only legal way to hail a ride, and lost most of that value when app-based services created an alternative supply the cap did not cover. An artificial scarcity is only worth what the barrier around it can hold, and this one was bypassed rather than broken.