NEW YORK: When someone asks Mr Roger Fierro 'What do you do?' he laughs. Then he says: 'I do everything.'

Mr Fierro, 26, has four jobs: as a bilingual-curriculum specialist for textbook publisher Pearson; handling estate sales and online marketing for a store selling vintage items; setting up an online store for a custom pinata maker; and developing reality-show ideas. So far this month, he has made about US$1,800 (S$2,200).

While most 9-to-5ers have some kind of structure to their days, his can be wildly different. One recent day he worked on and off from 7am to midnight, including making business calls, working on the pinata store's website and visiting the vintage store.

'I have eight million things going on,' said Mr Fierro. 'It's exhausting. Sometimes I just want to take a nap.'

Some portions of the population - especially young, creative types like actors, artists and musicians - have always held multiple jobs to pay the bills. But people from all kinds of fields are now joining them. Mr Fierro, for one, has a degree in international studies and Latin American studies from the University of Chicago.

Some of these workers are patching together jobs out of choice. They may find full-time office work unfulfilling and are testing to see whether they can be their own boss. Certainly, the Internet has made working from home and trying out new businesses easier than ever.

But in many cases, necessity is driving the trend.

'There are two types of people in this position: the graduate who can't get a full-time job, and the person whose income isn't sufficient to meet his expenses,' said Mr Carl Van Horn, director of Rutgers' John J. Heldrich Centre for Workforce Development.

Entry-level salaries do not go far these days. A study by the Heldrich Centre found the median annual starting salary for United States graduates from four-year degree courses in the last two years was US$27,000, down from US$30,000 for those who graduated from 2006 to 2008.

Ms Maureen McCarty, 23, who graduated from American University last year with a journalism degree, makes US$25,000 a year as managing editor of TheNewGay.net, a blog on gay issues.

The salary does not cover her expenses, so she often baby-sits five nights a week for another US$5,000 a year.

All told, Ms McCarty says, she works 75 to 80 hours a week, a schedule more typical of investment bankers or lawyers aspiring to make partner in a firm - but for just a fraction of the pay.

On the brighter side, when or if these job jugglers get on a career path, they may offer an attractive skill set: They are expert multitaskers, hyper-organised and often very knowledgeable in technology. Having multiple jobs is an exercise in mental dexterity.

But beware: Too much multitasking makes it harder to sustain attention, according to University of Southern California assistant professor of communications Kirk Snyder, who researches Gen Y's changing workplace values.

'Being focused on more than one professional pursuit... makes it easier to give up on those pursuits that take more effort or have a longer pay-off curve because there are always other options to focus on,' he said.

More damaging may be the economics. A study by the Johns Hopkins Institute for Policy Studies found young women who worked primarily in part-time jobs did not make higher wages in their 30s than in their 20s.

The reason is that part-time jobs generally provide fewer training opportunities and often do not put workers on track for advancement.

Prof Snyder does not see multiple job-holding as a trend that will disappear any time soon.

'The likelihood of this generation devoting their professional life to just one job or career at the same time is simply counterintuitive to their world view,' he said. 'I think we would be seeing this generation pursuing multiple jobs and careers at once even in a robust economy.'

Still, is job-juggling really sustainable, particularly when the next stage of life hits and there may be a mortgage and children?

Ms McCarty does not think so, saying: 'I don't want to be 30 and working a bunch of small jobs so I can pay my bills.'