Though Friday's job report showed the nation added nearly 200,000 jobs in June, the number of people working part-time due to slack economic conditions rose sharply.
The number of people unable to find full-time work rose by 322,000 to 8.2 million last month. This figure had been decreasing from a peak of 9.1 million in mid-2009.
The latest monthly payroll gains once again were led by restaurants and bars, which added a combined 52,000 jobs. The leisure and hospitality industry, as a whole, accounted for 75,000 of all the net job growth in June.
These businesses on average offer fewer hours of work.
The long-term implication of part-time work, economists said, is growing wage disparities and the risk of dampening consumer spending, a major driver of the economy. Part-time workers also are more likely to rely on state aid, such as food stamps, to make ends meet.
Michael Bernick, former California Employment Development Department director, has noted that various industries are increasingly relying on part-time workers and other contingent employees to save money.
"As you have more and more costs associated with full-time workers in terms of healthcare or other costs, employers look for alternative ways to reduce costs," Bernick said in February. "One way is on-demand and part-time work."
The increase isn't limited to industries that typically employ part-time workers, such as leisure and hospitality. Other sectors with strong job growth, such as professional and business services, have also seen a rise in part-time workers as employers aim to keep payroll costs down, Bernick said.
Some economists say employers are also cutting worker hours to avoid paying for health insurance benefits ahead of the rollout of President Obama's healthcare law. Earlier this week, the administration delayed a key part of the Affordable Care Act: penalties on large employers who don't offer health coverage will not be imposed until 2015, a year after it was originally set to take effect.