Much has been written both here in Los Angeles and nationally about the resurgence of organized labor. Yet to a large extent, this “renaissance” has been limited to a few sectors, largely tied to public or non-profit institutions, or to areas like ports, casinos and hotels where there is a heavy investment in fixed facilities.

The problem for labor is that these sectors, although important, do not represent the cutting edge of the new economy. Most of the employment today comes from small, service-oriented firms that maintain a limited investment in fixed equipment. They are highly mobile, most particularly those in fast-growing sectors such as high technology. If a union wants to organize these companies, they can easily move to another location, whether in the United States or elsewhere.

Perhaps most disturbing for labor has been the rapid growth of part-time and contingent workers. Part-time workers now account for more than 17.5 percent of the labor force. Manpower Temporary Services is now the nation’s largest employer. Such workers are notoriously hard to organize, since they shift jobs and can usually be fired at will.

This “e-lance” economy a term coined by MIT’s Robert Laubacher includes a large swath of workers, including many in modest professions such as clericals, assemblers and key-punchers. But increasingly it is at the higher ends of the “knowledge value” economy that contingent work is becoming predominant. Today we don’t only have itinerant dry-wallers, but “software gypsies” and “hired-gun” animators.

The growth of this “e-lance” economy is evident in two of the most important growth sectors of the economy entertainment and high technology. Silicon Valley is a perfect case in point. Even when the valley economy was weak in the early 1990s, temporary work continued to grow. Today as much as 40 percent of the employment base in the valley is part time.

This marks a major change from previous practice, notes Bob Brownstein of Working Partnerships, a labor-backed group trying to organize part-time workers. In the past, “dinosaurs” such as Hewlett Packard and Intel were notable as enlightened, if hard-driving employers. They did much of their work in-house. Today the new model high-tech firm such as Cisco or Oracle employs fewer workers and relies on contingent labor and subcontractors. Unions are virtually unknown.

“Now the high-tech companies tend to keep only a core of employees who are very well paid, and they will do anything for them,” Brownstein observes. “Everything else is outsourced. It’s a winner-take-all society.”

Life for those inside the companies, as Brownstein suggests, tends to be very good. But for those on the outside, often working on short-term contracts with no stock options or benefits, the Silicon Valley dream can prove a nightmare. Wages for these workers in the valley, as elsewhere, have been stagnant or declining in real terms.

The situation in Hollywood is similar, and perhaps a bit better for the workers. Among the industry’s employees, only 80,000 work directly for studios and independent producers; 146,000 labor as freelancers, writers, directors or craft specialists. Unlike their Silicon Valley counterparts, some of these workers are unionized or at least operate in a union environment, which tends to keep wages and benefits up. Silicon Valley organizers like Brownstein see Hollywood’s unions as a potential model.

Yet despite this, the situation in Hollywood, as in Silicon Valley, is not rosy for unionism unless organized labor changes. The very nature of the new economy, with its blurred distinctions between work tasks due to the impacts of new technology, have upset hierarchical arrangements characteristic of conventional agreements. The ability of producers and studios to offload unionized work to non-union locations, both domestically and overseas, further weakens labor’s hold.

This weakening can be seen in the current alignment of organized companies. The traditional players the major studios like Disney, Warner Bros. and Fox are unionized, as they have been for generations. But many of the newer players, including virtually all the digital houses, remain unorganized.

“We have Ford, GM and Chrysler but we don’t have Klasky Csupo, Film Roman or Digital Domain,” complains one labor activist. “We are like old industrial unions who can’t find a way into the new economy.”

To thrive in the 21st century, whether in Hollywood, Silicon Valley or other new-economy hotbeds, this labor official suggests that unions will have to change. They may have to emphasize less hierarchy and more up-skilling of their workers. In some senses, they will have to become more like medieval guilds than mid-20th century industrial unions more an association of artisans than a group of undifferentiated workers.

Whether labor is up to this challenge will likely determine its fate in the next century. If it becomes little more than the representative of public workers, labor will become increasingly tied, not to the growth of the economy, but to the demands of taxpayers. This is not the dynamic of a growth movement. But if labor can tap into the real needs of workers in the new economy in terms of education, health benefits and other issues organized labor’s role in the next century will be all but assured.

Business Journal columnist Joel Kotkin is a senior fellow with the Pepperdine Institute for Public Policy and a research fellow at the Reason Public Policy Institute.