The fallacy at play is thinking that every company knows exactly how many people will be hired. Some times we hire by budget: The department has $X million to expand headcount and how fast it goes depends on the seniority and skill level of the applicants we get. Or maybe the first few people we hire are moving faster than expected so we raise the bar and start being more selective to match the people we just hired.

There are infinite reasons that a job listing may not get marked as filled within a short timeframe used in these studies. I know some people want strict requirements or things like fining companies who don’t hire someone in time, but the majority of postings that fit this definition are not “ghost jobs”.