Catherine Rampell, economics writer for The New York Times, last week wrote a piece titled, With Positions to Fill, Employers Wait for Perfection. In it, Rampell explains how post-recession employers string along job applicants for weeks, sometimes months, stepping them through multiple rounds of interviews and strapping them with test assignments before finally making a hiring decision. And that decision is often to not hire anyone at all; rather, to leave the position unfilled.

So then why interview candidates in the first place?

Ms. Rampell cites a “hiring paralysis,” resulting from employers’ unease about the future of the economy. While a fair reason to slow the hiring process, this doesn’t explain why employers sometimes interview candidates for jobs that they know will never be filled.

Here’s some insight. In mid- and large-size companies, upper management often fails to communicate downward its decision to hold off on hiring, and so unit directors move forward with legitimate plans to recruit and on-board staff. It’s only several weeks later when the CFO or HR Director won’t approve the offer letter that the hiring manager realizes they’ve been spinning their wheels. Meanwhile, smaller firms might post jobs just to seem competitive and interview candidates in order to test the job market, or fish for information about competing firms.

Having nothing to do with the economy, companies large and small are notorious for interviewing candidates despite already knowing exactly who they plan to hire. Well-meaning HR Directors feel their hands are tied by equal-opportunity hiring laws that require so many candidates to be considered before an offer is made—even though there’s zero chance that any of those candidates will be hired.

Make no mistake. It’s disrespectful, unprofessional and unethical of employers to have candidates prepare for and go on phantom interviews that sap their time and resources. And it can come back to bite them in a number of ways:

Jobseeker Retaliation. When an organization mistreats its candidates, word gets out. Thanks to forums like LinkedIn and glassdoor.com (a community that offers an inside-look at companies’ hiring practices), frustrated job candidates post negative opinions despite potentially labeling themselves as complainers (note: glassdoor permits anonymity). Over time, these social media digs can have a lasting negative impact on a company’s reputation.

Candidate with an axe to grind. A candidate who manages to “ride the bull” until the bitter end of a lengthy interview process may ultimately accept a job offer, but begin their new role with a residual bad taste in their mouth. An employer should not be surprised to learn that the person they’ve hired is not the same person they first interviewed six months ago. The person you’ve just hired is tens of thousands of dollars poorer than they were when you first met them and they’re no longer high on your company’s culture. They’re harder to win over and retain than they would have been had they been treated more fairly during the interview process.

No more employee referrals. Though I like her article, Ms. Rampell does not mention that companies proudly continue their internal employee referral programs amidst hiring slow-downs and freezes. They continue to incentivize staff to tap their contacts in order to find suitable candidates for supposedly available positions. In theory, employee-referred candidates should be handled with special care—not led down a dead-end. When this happens, the referring employee is left with egg on his face at best; a damaged reputation at worst. And despite the monetary incentives for referring candidates (often $1,000+ per referral), top talent will only subject so many of their contacts to mistreatment, and so, when a company decides it’s ready to hire for real, they find their employee referral program—statistically where the best candidates comes from—has dried up.

What’s a candidate to do?

It behooves employers to treat jobs candidates with fairness and respect. It’s a no-cost investment in their reputation and longevity with plenty of upside. But candidates can’t count on employers to do the right thing. Jobseekers: Whatever else you do, stay vigilant. If you feel like you’re getting strung along…if your interviewer is clearly not prepared or interested to deal with you…if they change your interview schedule over and over again…if they make you wait for an hour before seeing you, it’s a sign that your interview is a farce. While it’s hard to do when you don’t have an offer on the table, limit the amount of time you put into this opportunity and consider removing your name from consideration if you’re asked to complete an assignment. You need to focus your energies where you feel you’re making progress.