Put some money on the line. I'm not an economist but you could structure a market where you cannot just take up mental space in the job market for practically nil. That's the current malincentive, that companies put up job listings they have no intention of filling, even when candidates who are qualified by their own criteria apply. The current job market maladies are a perverse incentive of the price of posting a job and applying for a job are effectively nil, the spread is too big for anyone to make the trade.

Good point. Verifying that a company exists is relatively easy, but confirming that the role is actually open and actively being hired for is definitely harder. I was thinking verification could include confirming the recruiter’s identity and requiring employers to periodically confirm that the position is still active. Ghost jobs are definitely an important challenge.