Since losing her job last April, Laurianne Dobbins has known one thing: she wasn't going to let her skills get rusty.

So the 45-year-old mechanical designer bought a training edition of the drafting software she had used at work and practiced daily.

If you don't do it every day you can lose the skills, said Dobbins, from Rochester, New York. I didn't want that to happen to me.

She stopped her hobby of singing and missed out on outdoor pursuits with her family on weekends as she searched for work. In my situation I felt the need to justify all my time, she said. My whole lifestyle changed.

About four months into her job search she started volunteering 4-6 hours a week at a local hospital, working in the project engineering department.

Her fight to stay on top of her game is central to a key economic debate in the United States. At what point do people who have been unemployed for several months become unemployable? And how can they stop that from happening?

In occupations that are more skilled and change a lot, if you haven't done something to keep up, the employer might think: Why should we spend a lot of our money over the next few months to get this person back up to speed? said Gary Burtless, senior fellow at the Brookings Institution.

But I would suspect that in more occupations, the only skill that atrophies is the ability to get up and go to work every morning.

U.S. long-term unemployment is now near its highest level since the government began keeping track in the 1940s, with 42 percent of the jobless out of work for more than six months. Of those, 37 percent hold only a high school diploma while 20 percent are college graduates, according to the Labor Department. (

And as unemployment drags on, it becomes harder to find a job. Those out of work for less than five weeks are more than three times as likely to find a job in the coming month than those who have been out of work for more than a year, according to Labor Department data. (

Perception, no doubt, plays a part.

If faced with choosing between two candidates, a personnel officer may lean toward hiring the person who is either still employed or has been unemployed for a shorter period.

Columbia University economics professor Till von Wachter says that is not necessarily a wrong instinct. One reason the long-term unemployed struggle more to find work may be that often they were simply harder to employ to begin with.

John Gehrke, 45, a systems administrator from Arvada, Colorado, whose last contract ended in June, said he's doing what he can to keep his edge -- but he is worried how his time without a job might look at his resume.

I am only concerned that an interviewer or organization will have a perception of me that my skills are not up to date, he said.

He's working toward an IT certification and is using micro-blogging site Twitter to keep up-to-date with technology companies and new developments.

Gehrke says he rarely watches TV and only on occasion do I allow myself a quick video game to refocus.

One thing people can do is try and find non-profits related to their industry, said Hallie Crawford, a career coach in Atlanta.

An architect she coaches has been volunteering on Atlanta's BeltLine redevelopment project, a network of public parks and transit along a historic 22-mile railroad corridor circling downtown Atlanta, she said.

Keeping motivated, however, can be tough if the job search leads nowhere.

People tend to get depressed and want to stay home and watch TV, Crawford said.

But even while Crawford encourages getting involved in nonprofits, she admits there is no clear evidence how much those efforts help in actually landing a job.

And as long-term unemployment becomes virtually institutionalized, the impact of those jobless workers fades on the broader picture of employment. Opportunities for rising wages can start to occur even with a high unemployment rate -- a worry for central bankers.

Europe in the late 1980s offers some evidence that as more of the unemployed are out of work for a longer period of time, the less and less influence their presence has on the wage bargains being struck between current workers and their employers, Burtless, of the Brookings Institution, said.

They become invisible in the job market.

(Editing by Leslie Adler)