Take for instance a proposal that says "no one is allowed to sell their used car for less than $10k". Maybe the justification is poor people are desperate and sell their car too cheap and all these dealerships and buyers are a monopsony underbidding the real value of the car, profiting off these uninformed, unorganized individual sellers.
Does anyone think this is a good idea? Would anyone bother reading studies contemplating the effect this may have?
No, of course not. Everyone knows that this would essentially mean many cars that would have sold under $10k would just not get sold. Sure some people would benefit, maybe getting a higher price for their car. Some things would shift, maybe people would opt for scooters or e-bikes or something.
But I wouldn't want this price floor if I was on either side, trying to offload a bad car or buying one.