Part-time or part-time seasonal workers can be lumped together to count as full-time equivalent.

WSJ: Companies With 50 Employees in 2013 Will Need to Provide Insurance

Large employers (more than 50 full-time workers or the equivalent) must pay an assessment if they don't offer employees certain minimum coverage at an affordable rate.

WSJ: The Health-Care Overhaul: What Happens Next

ObamaCare requires companies with 50 or more full-time employees (or the part-time equivalent) to provide their workers with health insurance beginning next year.

FORBES: It's Not Just The Minimum Wage, It's Also The Health Insurance Mandate

They contribute 1.2 billion hours each year to sport, the equivalent of 720, 000 full-time paid workers.

BBC: Davies backs volunteer drive

That is the equivalent of 3.8m skilled workers toiling full-time, year-round, just to handle the paperwork.

ECONOMIST: A futile plea for simplicity

As demand for crowdsourcing labor grows and technology improves, Mr. Robertson adds, workers can now make the equivalent of full-time annual wages from hundreds of temporary jobs.

WSJ: Small firms, Start-ups Drive Crowdsourcing Growth