If you're feeling that your employment situation is more precarious than it was a decade ago – or in the case of younger workers, if all you've known is precarious employment situations – you're not alone. According to a March study by a pair of Harvard and Princeton academics, workers in "alternative" employment such as on-call workers, temp-agency workers and independent contractors, accounted for a much larger share of the workforce in 2015 than they did in 2005.

More strikingly, the study finds that – emphasis in the original – "all of the net employment growth in the U.S. economy from 2005 to 2015 appears to have occurred in alternative work arrangements."

Lawrence F. Katz of Harvard and Alan B. Krueger of Princeton, who used data from the Bureau of Labor Statistics (for 2005) and a RAND survey (for 2015), found that total employment increased by 9.1 million jobs to 149.4 million between February 2005 and November 2015. During the same period, the share of workers in alternative arrangements increased from 10.1% to 15.8%, which Katz and Krueger calculate to mean a 9.4 million-job increase to 23.6 million. 

Of course, not every new job during this period was an alternative arrangement. Plenty of people got full-time jobs with health care and other benefits. But plenty also left such jobs, willingly or not. In fact, 0.4 million more left these cozy jobs than gained them. What expansion the total workforce did see, meanwhile, is due to the 66.5% growth in the gig economy. More, in fact. (See also, The Rise of the Gig Economy.)

The industries that have been most affected include education, health, public administration, transportation, retail and manufacturing. The share of gig workers in the professions and construction actually decreased, but they are the exceptions.

Katz and Krueger were not able to isolate the effect the Great Recession had on the rise of alternative employment arrangements, but they find it "plausible" that the job losses it triggered in part explain the trend. They also see technological change as having reduced transaction costs associated with hiring contractors for individual tasks. Also possible, they say, is a demographic shift: older and more educated workers are more likely to work in alternative arrangements, and the workforce is becoming older and more educated overall. (See also, Most Americans Don't Know What the 'Gig Economy' Is.)

Opinions vary on the extent to which this shift has helped or hurt workers. Employment arrangements such as driving for Uber Technologies Inc. offer flexibility, and independent contractors often take pride in being their own boss, but salaried work tends to offer better pay and stability. Katz and Krueger plan to analyze gig economy workers' earnings and hours in later work. For now suffice it to say that whatever the gig economy is, it's growing, even as the traditional labor market shrinks.

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