There always have been part-time jobs. Some workers want them. Some employers provide them out of financial and scheduling necessity.
Since the Great Recession began, though, the proportion of involuntary part-time employment has grown. Some employers are preparing to reduce their health-insurance coverage responsibility for full-time employees under the federal health law's universal coverage mandate that takes effect next year.
When the economic collapse began in late 2007, an estimated 24.7 million Americans worked part time. That number now is 27.5 million, about one-fifth of the labor force.
A small share of the growth is fueled by workers' preferences. They're juggling school and work, or family and work, or downscaling their work lives as they near retirement. Part-time hours fit their needs.
But according to U.S. Department of Labor household surveys, most of the recent part-time job growth is not by workers' choice. In the latest national jobs report, covering April 2013, nearly 8 million workers - about one-third of all part-timers - say they were involuntarily part time.
The Labor Department classifies such involuntary part time as "for economic reasons." That means that only part-time hours were offered because of "slack work or business conditions" or job hunters could find only part-time work.
Indications also abound that employers around the country are turning full-time into part-time jobs to avoid the coming employee health care coverage requirements. Businesses that have more than 50 full-time-equivalent employees must offer their full-time workers access to a qualified health care plan or pay a penalty of $2,000 a person. The health care law defines a full-time employee as anyone working more than 30 hours a week.
That is a precedent-setting and low definition of full-time work, a member of the National Federation of Independent Business told Congress in April.
"This is already causing rescheduling of employees where public and private employers have read the law," says William Gouldin, a business owner who has provided health insurance to his full-time employees. "Every employer will be forced to define part-time employment as something below 30 hours per week, and most will use between 20 and 27.5 hours per week."
The effect will be that many part-time workers will lose hours and income they've been used to getting, or they'll be forced to add another part-time job to make up the difference.
"The new full-time employee definition will cause a hole in employment," Gouldin warned Congress.
A study released earlier this year by the University of California-Berkeley Center for Labor Research and Education estimated that 2.3 million workers, or nearly 2 percent of the workforce, are at the greatest risk for having their hours cut to below 30 hours a week.
But there are no statistics yet to prove that businesses are holding at 49 employees or cutting work hours to stay under the 30-hour rule. A small survey by the Federal Reserve Bank of Minneapolis found 4 percent of companies were moving toward a larger part-time workforce because of health reform.
Some employers have publicly acknowledged they're cutting workers' hours because of the law. Among them: Regal Entertainment Group, whose movie screens include the Edwards theaters in the Treasure Valley; the owner of Papa John's pizza chain, which has six Valley stores; a Five Guys franchise owner; an Applebee's franchisee; and a Denny's franchise owner.
Darden, which owns the Olive Garden, Red Lobster and LongHorn Steakhouse chains, announced and then backed off from a plan to reduce full-time workers to part time after a swell of negative national reaction.
Publicized or not, the part-time trend has become common enough in the service industry that workers have given it a name: the "Obamadodge," says Mike Enriquez, a labor advocate.
"It's happening across the board in retail, whether they announce it or not," Enriquez says.
The Idaho Statesman contributed.