Here is the bottom line:
If developers were allowed to face directly the high land costs of providing so much parking, the number of spaces would be a result of a careful economic calculation rather than a matter of satisfying a legal requirement. Parking would be scarcer, and more likely to have a price – or a higher one than it does now – and people would be more careful about when and where they drove.
The subsidies are largely invisible to drivers who park their cars – and thus free or cheap parking spaces feel like natural outcomes of the market, or perhaps even an entitlement. Yet the law is allocating this land rather than letting market prices adjudicate whether we need more parking, and whether that parking should be free. We end up overusing land for cars – and overusing cars too. You don’t have to hate sprawl, or automobiles, to want to stop subsidizing that way of life.
Here are a few quotations from the article:
“Minimum parking requirements act like a fertility drug for cars.”
As Professor Shoup puts it: “Who pays for free parking? Everyone but the motorist.”
If we don’t give away cars, why give away parking spaces?
What are the biggest problems with the idea? First, the danger of spillover parking means that a lot of parking has to be properly priced all at once. If the local K-Mart has a smaller lot, you don't want the customers flooding a neighborhood street and simply shifting the problem. The proper correction requires a coordinated pricing and enforcement effort, not only to succeed, but also to be sufficiently popular with homeowners. Fortunately, most of the coordination can be done at the level of the individual town or city.
Second, we don't yet know how many more spaces would be priced in the absence of legal minimum parking requirements, and how many fewer car trips there would be, especially if we are holding the quantity and quality of mass transit constant. The employer still may wish to subsidize appearance at the workplace. Alternatively, "parking fees as lump sum tax" is fine by me and it bears an odd but pleasant connection to Georgist ideas. Another possibility is that a lot of parking is shifted to satellite lots, combined with small buses or shuttles; Tysons Corner Mall already does this at Christmas or consider any number of airports. That still would improve land use (and welfare), but it remains an open question how much congestion and emissions would get better.
Mark Thoma discusses some distributional issues. I would note that less land for parking should lower other real estate and retail prices, even if more poor people end up taking the bus. And the very poorest Americans often don't have cars at all.