MORE PEOPLE are now unemployed than at any time since the Depression. It's also likely that, even when recovery comes, the unemployment rate will remain higher than it was before the current recession. Partly that is because severe unemployment upsets normal career patterns, discourages employers from investing in the training of workers and accustoms workers to relying on unemployment insurance for at least part of their income. But something else is at work, too. The economy is changing rapidly, and it is leaving the labor force behind.

Labor market forecasters see a burgeoning of jobs in occupations that didn't even exist two decades ago. Engineers and computer programmers are already in short supply and likely to become more so as the defense buildup proceeds. There are also new demands for people trained in such exotic subjects as genetic engineering and design and management of fully automated production lines. Meanwhile, less-skilled jobs will be vanishing as government shrinks, clerkships are replaced by automated filing systems, and robots take over from assembly-line workers.

Left to itself, industry will, no doubt, meet its own needs for skilled workers. It may do that, however, in ways that are painful to many people and costly for the nation. For example, jobs may be exported--or workers imported--at higher cost than if the unemployed were trained to fill them. Labor- saving automation undertaken without regard to the long-term costs of capital and energy may reduce rather than increase the productivity of the nation's resources. And a large and growing number of more or less permanently unemployed is not only a major social problem but a likely source of backlash against needed industrial change.

The administration has spent generously to stimulate additional investment in plant and machinery. Its policies, however, seem not to recognize that labor is an equally important factor in produc tion. Much of the CETA system has been dismantled and the state-run Employment Service--a major placement agent for lower-skilled workers-- has been cut by a third. More cuts are apparently planned. These programs were far from perfect, but they worked reasonably well, and much has been learned about how to make them work better.

The House and Senate labor committees have reasonable proposals for replacing CETA when it expires this year. Developing human capital--no less than upgrading plants and machinery--takes time and money, however, and the Reagan program calls for fast results and lower budgets. But it calls for higher productivity, too. Administration planners might want to remember that fancy equipment can't be designed, installed, operated and maintained without a skilled work force on the job.