Just as many companies won’t hire the unemployed, new research suggests workers may tend to avoid jobs that have been open too long. A look at high-growth areas like Silicon Valley reveals some big disconnects between the expectations of tech job employers and job seekers – leaving many positions open and many professionals unemployed.

Finding a tech job these days should be as easy as shooting fish in a barrel, right? Not since the dot.com boom of the late 1990s have so many companies sprouted up with a mission to create software and provide online services to the masses. Heck, even jobs in general seem to be making a comeback. The U.S. Labor Department’s national numbers on unemployment claims dropped to 7.8% from 8.1% last week.

That optimism might be overheated, however. Information technology-related jobs (IT jobs) saw reductions of 1,700 workers last month, according to research released this week from Foote Partners Research Group. That’s the first monthly drop in IT industry jobs that was not labor related since 2010. Compared to earlier this year, unemployment for IT workers mostly befell Web developers, network architects, computer systems analysts and software developers, according to the Bureau of Labor Statistics.

Not Time To Panic For Tech Workers

While not cause for full-scale panic, the decrease hints at a broader industry problem: Employers can’t find enough qualified employees even as job seekers can’t find qualified openings.

In a perfect world, every manager fills open positions as quickly as possible. But even as many workers can’t find appropriate positions, the market for technology professionals in certain geographies and skill-sets is remarkably tight.

Some 45% of surveyed hiring managers and recruiters told Dice.com it was taking longer to fill positions relative to last year (June 2012 compared to June 2011). The number one reason, according to Alice Hill, managing director of Dice.com: an inability to find qualified professionals. That was followed by hiring managers being more discerning waiting for the perfect match.

The problem is that waiting for the ideal candidate may mean job postings remain open for longer than some job seekers are comfortable with. The longer a job is open, the less likely it will get filled, according to Randstad Technologies a technology recruiter based in the U.K.

Does A Job Posting Have A Shelf Life?

To test its theory that employers should not keep job postings open indefinitely, Randstad contracted a survey of 2,001 people asking, “How many working days does a vacancy for a permanent job have to be open before it starts to look like a bad job that no one wants?”

Technology professionals in the U.K said they thought a post that was vacant an average of 67 days was most likely a job that no one wants. The survey did not indicate what kinds of employers had postings that lasted that long, nor what kinds of jobs could not be filled in more than two months time. Typically, online job posting websites like Dice.com, CareerBuilder.com and SimplyHired.com keep each posting for only a month. Most fill up in two weeks time, according to Dice.com’s Hill.

Just as important, there could be many reasons why it’s taking longer to fill a particular position and not necessarily because it’s a “bad” job.

“There are instances where consulting or staffing companies are constantly in need of certain professionals,” Hill says. “The job may appear to be the same, but it’s really a unique role with similar qualifications and experience needed.”

Testing The Theory In Silicon Valley

Does this theory really hold true – especially in the hyper-competitive market of Silicon Valley? To find out, we took a look at job listings for tech positions listed on four well-known job-search sites for in Cupertino, Calif., the home of Apple.

It seems that some employers do have a hard time filing software developer jobs. A simple search turned up the following un-filled positions posted for more than a month:

Dice.com

Careerbuilder.com

CloudSystem Software Engineer – VI for a high-profile company in Palo Alto – posted 3 weeks ago

Software Developer at a lesser-known company – posted 3 weeks ago

Simply Hired

Sr. Software Dev Engineer Wireless at a high profile company in Seattle – posted 29 days ago

Software Development Engineer in Test Framework at a high-profile company in Seattle – posted 17 days ago

Craigslist

SW. Developer – Music Apps at an unknown company – posted September 8

Senior C/C++ Software Developer at an unknown company – posted September 7

Job Postings Are Like Real Estate Listings

“Recruiting for a tech post is like trying to sell your house. Leave it on the market too long and, for whatever reason, people start to think there is something wrong with it,” said Mike Beresford, managing director of Randstad. “That leads to fewer applications and increased pressures on the rest of the staff left trying to cover the empty position.”

While IT jobs continue to be in high demand, the nature of employees and those looking for work in tech remains a dance between employers looking for skilled workers and skilled workers looking for better opportunities.

It may seem that in this economy, just posting an open position should be enough to get it filled. But as the research shows, it’s also important to manage expectations – and to refresh job listings left up too long – if we want to get those positions filled and people back to work.

Images courtesy of Shutterstock.