The length of your job hunt varies based on your industry in the United States, according to job review site Glassdoor’s 2017 analysis of over 83,000 job interviews. Among U.S. cities, there were three industries that took the longest to hire: government (53.8 days), aerospace and defense (32.6 days), and energy and utilities (28.8 days). Meanwhile, professionals looking for jobs in restaurants and bars (10.2 days), private security (11.6 days) and supermarkets (12.3 days) had the shortest interview-to-hire processes.

“It’s easier to look for a job when you already have one” is the pragmatic advice my professor once told me. Turns out, research backs him up. When a group of economists looked at the job-seeking strategies of 2,895 adults ages 18 to 64, they found that people who already had jobs generated more interviews and more unsolicited recruitment offers than people who were unemployed and spending seven times as much of their time actively looking for a job.

“Searching while unemployed is much less effective in generating offers than searching while on the job,” economists from Columbia University and the Federal Reserve banks of Chicago and New York concluded.

If you are out of work and job hunting, you need to be able to account for your time away from the labor force on your résumé and to recruiters, Watkins said. One way to do this is to maintain your industry skills and “show that you haven’t stepped away and lost your touch” by providing your service to a community organization, she said.

This is when it gets significantly harder to find a job.

After you’ve been out of work for six months, the government considers you “long-term unemployed” in the U.S., and this distinction has a stigma.

Research from the Federal Reserve Bank of Boston has found that after U.S. workers are out of work for more than six months, it gets harder for them to get out of unemployment.

Ofer Sharone is an associate professor at the University of Massachusetts Amherst who focuses on unemployment and founded the Institute for Career Transitions to support long-term unemployed job seekers. Sharone said that the long-term unemployed disproportionately tend to be older workers and African American workers.

“For some people it takes longer, they don’t get a job right away,” Sharone said. “And that could be just sheer bad luck. There’s a lot of randomness in this process. But likely there’s also patterns of discrimination.”

Sharone described the jobless trap for long-term unemployed professionals as a “black hole” in which they apply and hear no reply because they are being systematically filtered out due to employer bias.

Even lowering their expectations doesn’t help people in this group.

“Those jobs are also blocked off to them because they are perceived as overqualified,” Sharone said. “Lots of recruiters say, ‘Hey, someone who has 10 years’ experience applying for a job that only requires five years of experience ―I’m not even going to look at them because they are going to be bored, they are going to expect more money.’”

During one field experiment when he was a visiting scholar at the Boston Fed, economist Rand Ghayad sent out 4,800 fake résumés responding to 600 job openings, varying how long these fictional job seekers had been out of work and how much experience they had, while keeping their male gender and education background constant.

For the fictional job seekers who were out of work for less than six months, employers were more likely to give them a call back, even if they had less experience. But employers were much less forgiving when the applicant had been out of work for more than six months. Regardless of their prior experience, job seekers with six months of no employment got significantly fewer interview requests.

Sharone said one ironic twist is that in economies with low unemployment, the stigma against long-term unemployment can be stronger and “the recruiter will say, ‘My God, the unemployment rate is so low. How is it that you’re six months or one year unemployed?’”

If you’ve been job hunting for a while with no luck, here’s what to do.

Instead of worrying whether your job search is measuring up to your peers, focus on what you can control. To speed up the job process and maintain your hope, there are a few key actions experts say you can take:

Find your support system. If you are among the long-term unemployed, Sharone said you need to “see it as a marathon and to be in this marathon, you need to take care of your well-being.” To do that, you need to make sure you’re not isolated, and instead, “find others who are in your same boat” through a job-search group, he recommended.

Track your progress to find what is and isn’t working. Watkins said tracking your job search outcomes can help you see where the breakdown is. “If you’re getting the interview but you’re not getting offers, then you want to backtrack and say, ‘Well OK the interview may be the issue,’” she said. In that scenario, ask someone do a mock interview with you, Watkins said.

Prioritize networking. Watkins estimated that career changes like relocating and switching industries can add an additional three months to your job search. To cut down on that time, she advised networking and marketing your skills ahead of when you are planning to make that change. “The things that you do before you need a job ― they usually go hand in hand with how you are successful with your job search,” she said.

For job seekers who are unemployed long term, networking is “the one thing that can break through the bias,” Sharone said. Getting a person on the inside of a company to vouch for you and say, “Hey, you should take a look at this person, because they’re really good or I’ve worked with them before” can “stop that automatic screening out,” he said.