(I am an elected politician on the Board of Directors of a special district, one power of which is related to residential parking permits, and am additionally on a community committee working on improving the parking situation in the business area; my job on this committee is to do the actual outreach to local businesses. Note also that I am someone who believes in decreasing the use of cars.)

Your suggestion essentially turns into a game theory problem of "is it better to construct parking for my business or be located next to a business that was dumb enough to construct parking, as many of my customers who really would have wanted parking will end up just parking there, they will get the ire of anyone who actually gets towed, and that assumes they also have any good mechanism to decide who to tow anyway.

Requiring each building in a business area to have its own attached parking is a great way to perpetuate sprawl. Successful walkable business districts either use metered street parking, or intercept cars in parking lots at a stand-off distance away from the shops themselves. This amortizes the parking load among the shops.

If that sounds a lot like a mall, it is, but I'd advocate for also removing the zoning restrictions that segregate residential condos from business (a really stupid decision that many American cities keep perpetuating).

This is a different suggestion: removing parking at businesses and centralizing it using government (which does not lead to the problem I mentioned).

Maybe we could place that government parking on the sides of existing roads; we could automate the payment process with small devices mounted on posts that could take coins (or in some places, cards or mobile payments). For people who don't pay, we could have city employees walk around and issue fines for non-compliance...

In my city it's common for large retailers to provide parking lots at a cost. If you buy something, the cashier gives you a stamp that nulls your parking charge. Anyone can park, but free for customers. There's ways to game it, but it seems a workable solution.

I've only seen parking validation for private garages. Are your parking spaces owned by the city, and retailers can still validate for downtown, on-street parking?

In my hometown's downtown we have large parking towers that provide parking at fairly cheap rates. In the city owned one, the first hour is free. It's actually a lot more convenient than hunting for parking at area X, hoping there is street side parking or a parking lot. We also get a walkable downtown as a result too.

So instead of requiring a business to have parking, ban the creation of parking and mandate the creation of parking towers or lots financed by business property taxes instead. You get denser, nicer downtowns as a result. You can similarly socialize parking in less dense areas by banning business from having free parking lots and making a few city ones instead.

I agree: the suggestion I was replying to was to remove regulation and try to let the market come up with parking, which this suggestion is clearly not anything similar to ;P.

Parking lots can exclude people. It isn't a public good.

And in what is probably the first mental association most people have with parking lots, they're also rivalrous.

Right. That is, in fact, the point, and why the suggestion to remove regulations and to just let the market regulate parking ends in combat and a bunch of people trying to game theory each other's parking... the result is everyone hates each other and is clearly unfair (if potentially efficient).

Imagine the horrors if we let the market regulate cabinet space in your kitchen.

Once you remove the subsidy people pay to park. What is so unfair about that?

Then nobody will go through the expense of building any parking for their development, after which everyone suffers. New owners will have to build parking simply to exist in the space, and a great gap forms between affordability for owners who were there before vs new owners coming in - less traffic means all the businesses suffer.