More than half of full-time employees who moonlight at secondary part-time jobs do so just to "keep up with increased cost of living," according to a study released Tuesday by employment and research site Indeed.

And with home and rental prices expected to climb further in 2016 against a backdrop of expected inflationary pressures, it's unlikely living expenses will get a whole lot cheaper as the year goes on. Perhaps as a result, almost 90 percent of 2015's moonlighters expect to keep up with their side jobs in some capacity during the new year.

"Employers have been slow to raise salaries despite increasingly strong demand for workers in 2015, and this survey shows many wage earners don't expect that to change in 2016," Tara Sinclair, Indeed's chief economist, said in a statement accompanying the report.

Out of more than 3,000 people surveyed by Indeed, more than one in three "did some other kind of work to supplement their income in 2015," according to the report. Though about 16 percent said they moonlight because of a changing family situation and another 14 percent wanted to explore a new career, more than half of full-time employees who balance part-time gigs said they did so just to meet living expenses.

"While many people take on part-time jobs for extra spending money or as a hobby, the survey shows the majority are working to make ends meet, a situation we hope to see change in 2016 as a stronger economy boosts wages," Sinclair said.

About 4.9 percent of all employed Americans in November worked multiple jobs, the vast majority of whom worked a primary full-time job on top of a secondary part-time job, according to the Bureau of Labor Statistics' most recent employment report.

Women are more likely than men to work two or more jobs (5.5 percent of all working women in November, compared to just 4.7 percent of men on a seasonally unadjusted basis), and young workers, particularly those between the ages of 20 and 24, command a higher percentage of moonlighters than other age demographics. About 5.8 percent of young Americans held more than one job in 2014, according to the BLS. That percentage dropped to just 4.4 percent of those at least 55 years of age.

Overall, instances of moonlighting have dropped from recessionary highs. The rate of Americans holding multiple jobs spiked up to 5.6 percent in August 2008 and has gradually come down. But that uptick hardly represented an all-time high. The U.S. multiple jobholders rate peaked at 6.5 percent in Nov. 1996. The U.S. was several years removed from the recessionary turmoil of the early 1990s and still a few years away from the dot-com bubble crash that would help bring about a brief recession of 2001.

The rate ticked up slightly during the Great Recession but has been trending downward for the better part of the last two decades. Contrary to anecdotal accounts of Americans being forced to take on multiple jobs to get through the aftermath of America's worst financial downturn since the Great Depression, there's actually a smaller percentage of workers juggling two jobs today than there was 20 years ago.

"Many people may think that, because of the tough economy and stagnant wage growth, more and more people are working multiple jobs," said a 2014 Pew Research Center report. "However, that assumption would be wrong. Both in terms of raw numbers and as a share of all employed people, fewer Americans are working more than one job than in the mid-1990s."

Indeed, the BLS estimates about 7.39 million Americans held multiple jobs in November 2015. That number was as high as 8.31 million in November 1996, when the U.S. held more than 51 million fewer residents.

"Multiple jobholding declined in the United States during the past two decades," the BLS said in a report published last year based on data that was current through 2013. That study concluded that multiple jobholders "did not become more likely to return to single jobholding."

So the Indeed study's findings that 90 percent of moonlighters will stay the course in 2016 isn't terribly jarring. The trends it profiles have been in the works for the better part of the last 20 years. What's more alarming, however, is that the majority of these multiple jobholders are stretching themselves thin to keep up with the country's rising cost of living.

Higher interest rates throughout 2016 are expected to make borrowing money more expensive, and inflationary pressures could raise costs of goods and services. It will ultimately be up to employers to boost wages in the coming months to keep millions of Americans' heads above water. But the last few years have proven to be largely mediocre for wage gains.

Average hourly earnings were up a respectable 2.3 percent year over year in November, but pay inflation is a dynamic that has only recently developed in the labor market. And although moonlighting is a great way for Americans to supplement their stagnant earnings and acquire new sets of skills, Sinclair expresses concern over moonlighters' reasons for taking on multiple jobs.