It's the economy, student loans, and the availability of convenient urban mass transit that's driving down the incentive to own a car.

If employed people (including cyclists) live in a densely populated urban area that has efficient mass transit, why in the world would they opt to buy a car first, before paying off their exorbitant student loans and other accumulated debt?

Of course, if they're unemployed, the situation already speaks for itself!

* While a driver's license is a great form of ID, most states also offer a common state ID that's acceptable too!