Sometimes people chuckle or look confused when I say I work in the gig economy. They think I made it up. I didn’t.

A gig economy is usually defined as an environment in which temporary positions are common and organizations contract with independent workers for short-term engagements.

Twenty years ago, I would have associated “gigs” with musicians. You play a gig at a club tonight, next weekend you play one somewhere else. Maybe you luck into getting a regular gig (almost an oxymoron) playing every other Friday night at the same place for a few months.

It is not “part-time” work.

The trend toward a gig economy has been climbing and a study by Intuit predicted that by 2020, 40 percent of American workers would be independent contractors.

What is pushing this trend to short-term jobs? One thing is an increasingly mobile workforce that can increasingly work from anywhere. Job and location are not always linked these days. Freelancers can select  jobs and projects around the world, and employers have a much larger pool of candidates.

Employers often like this arrangement as it means no office space needed and, as with part-timers in general, probably no benefits. Not being responsible for employees’ taxes and benefits allows companies to operate with 20% to 30% less in labor costs than the traditional competition.

People tend to change jobs more often throughout their working lives than in prior generations and the gig economy can be seen as an evolution of that trend.

Employers can contract with experts for specific projects who might be too high-priced to maintain on staff.

My newest gig is doing instructional design of online courses for a college. It is a one-year gig, so it is actually pretty regular work. But it is all virtual work from home and the hours are set by me. I have milestones and deadlines to meet, but the schedule is mine.

For this gig, I am getting an hourly rate, but the college has set a cap on the number of hours I can bill per course (though we have already discussed the possibility that some courses may run over that amount, while others will be under). The Dean in charge of this project would prefer to have an instructional designer full time on staff, but the budget line for that position won’t appear until next fall when their “virtual college” actually launches with student.

Gig workers like the improved work-life balance offered over most traditional jobs. Ideally, the worker is able to select jobs that they’re interested in – though obviously if you’re in need of work, you may have to take a gig that isn’t your first choice.

Despite any benefits, the gig economy is part of  the sharing economy, the gift economy and the barter economy and there are downsides to all of these. You are like freelancers and self-employed workers of the past and have to deal with insurance and other benefits and issues.

Finding hard numbers on the size of this gig economy workforce seems rather inexact right now. Government data sources have difficulty counting how many gig workers there are, but it is being tracked by the U.S. Bureau of Labor Statistics (BLS) and the U.S. Census Bureau.

Gig workers are seen in some government stats as contingent workers, defined as “those who don’t have an implicit or explicit contract for long-term employment.” Alternative employment titles also include those who identify as independent contractors, freelancers or independent consultants, on-call workers, and workers provided by temporary help agencies or contract firms.

BLS data lumps gig workers in with all the other alternative workers. The Census includes them in nonemployer statistics data – a self-employed individual operating a very small, unincorporated business with no paid employees.

Fast Company magazine warns that lawsuits around the gig economy are an issue of concern. Uber, Lyft and other gig drivers have protested and “gone on strike” and other companies that have built their business model on gig employees have seen some employee resistance.

Homejoy, Handy (both cleaning services) and workers on Amazon’s Mechanical Turk (an online platform that pays independent contractors cents per task) recently orchestrated a letter-writing campaign to Jeff Bezos asking for him “to see that Turkers are not only actual human beings, but people who deserve respect, fair treatment, and open communication.” Legally, Uber and Lyft are also facing charges of misclassifying workers. A case against an online work platform called Crowdflower was also opened.

What might bring down the gig economy? Besides some class-action lawsuits, there might be intervention by regulators (many cities are clamping down on Uber and Lyft at the behest of traditional taxi companies). If companies can ever hybridize traditional jobs and gig ones, you might end up with a new option that offers both the freedom and some of the benefits of traditional work.