>This is an odd claim to make. Regulation has historically required that it be provided in most (American) markets, hence the ample supply. I'm not sure how we could possibly know what the market would do on its own over the long term.
Sure we can. Those regulations are not always binding. Buildings are built with parking capacity in excess of minimums all the time.
>Requiring excessive parking will artificially and needlessly raises prices, true. But I would also be at least somewhat concerned that without sufficient regulation short term thinking on the part of builders might result in less parking than would be generally desirable.
Why? What's the market failure? For that matter, why is there a "general desire" for the quantity of at-home parking I individually consume?
>I'm not at all convinced that urban planning should be done by market forces alone.
That's a strawman — removing parking requirements is a far cry from "market forces alone" doing urban planning. (It is, however, a great example of how non-market forces can create worse, environmentally inefficient, undesirable outcomes by submitting what should be private choices to mob rule.)