NEW YORK (TheStreet) -- You can expect 40% of the U.S. workforce to be freelancers (or more technically, "independent contractors" by the year 2020.

"Traditional employment will no longer be the norm, replaced by contingent workers such as freelancers and part-time workers," Intuit said back in 2010. "The long-term trend of hiring contingent workers will continue to accelerate, with more than 80% of large corporations planning to substantially increase their use of a flexible workforce."

By hiring freelancers on (mostly) a project basis, companies can better control workflow and not having to dig into reserves to pay for such things as employee health insurance and employer-based retirement plans.

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Freelancers, meanwhile enjoy flexible schedules, no commute (in most cases) and have leverage salaried employees don't have, including a lower risk of losing all their income to a layoff or downsizing campaign, since most freelancers have multiple clients and can more easily absorb the loss of a single client.

Since you could be one of those four in 10 Americans freelancing, best to keep up on trends affecting them.

A new study, The Future of Work: Preparing for Independence, by the Career Advisory Board and MBO Partners, points to several key themes of interest to freelancers, would-be freelancers and companies of all shapes and sizes:

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Salaried workers are intrigued by the freelance lifestyle. "Career goals for contemporary professionals are changing and many are choosing self-employment in order to control the type of work assignments they pursue (67%), to have a greater sense of flexibility and work-life balance (64%) and to follow a passion (59%)," the study says.

A graying workforce? Freelancers "skew older in age than the overall workforce," the report adds. More than half of the survey respondents were boomers ages 51-66 (51%); another one-third were Gen Xers, ages 35-50 (30%); and only 4% were millennials, under the age of 35. That could be good news for younger workers, as more baby boomers leave the corporate world for the contractor life, opening up new, better-paid positions for the Gen X and millennial generations.

Social Media are not a factor. While some portions of social media are key to contractors' branding and reputation, Facebook, Twitter and LinkedIn, for starters, do not make money for them. "Just 6% said social media outreach led to paid project work," the study says. "Contract workers cited word-of-mouth referrals (82%) and assignments from former employers (47%) as their top two sources of project work."