As California's economic downturn begins to look more and more like the worst slump since the Great Depression, one key difference is emerging between this slide and past bouts of high unemployment in the state.

This recession, triggered by the collapse of the housing bubble, appears to be mostly cyclical, in line with the broad national decline. Demand for housing cratered for a time, and retail sales of everything from cars to clothes and computers have taken a hit as families have seen the value of their biggest investment shrink. This malaise has now spread throughout the entire economy, and it will likely not end here until the national economy begins to recover.

But none of the core industries at the heart of California's economy – computer technology, biotech, entertainment, tourism – seem to be suffering hits beyond their share of the cyclical slowdown.

This has not always been the case. In the early 1990s, Southern California's aerospace industry collapsed, and hundreds of thousands of manufacturing jobs disappeared, never to return. Earlier in this decade, a similar wipeout devastated the Silicon Valley, which suffered Depression-level losses of jobs while the rest of the country hardly felt a brief recession.

This difference is important for a couple of reasons. On the downside, it means that people who lose their jobs here have nowhere else to turn. In the 1990s, when the end of the Cold War led to a downsizing of the defense industry and the end of a half-century of California's dominance in aerospace, the state lost half a million jobs, and a million people left for elsewhere, because there were still jobs to be found.

The same was true after the collapse of the dot-com bubble in 2000. Silicon Valley lost 200,000 jobs, or 20 percent of its employment base, and many of those jobs never came back. But most of those who were laid off were able to find work elsewhere, either in California or other states. That's not true today.

On the other hand, although this recession is ugly across the board, so far there is no sign that any of the state's core industries are suffering more than the rest of the economy. Employment related to housing and construction has taken a bigger hit than jobs in other sectors of the economy, because California rode the bubble higher than most other states and had further to fall. But housing is not an industry unique to the state.

When aerospace and technology collapsed here, California's recession outlasted the rest of the nation. This time, the recovery should track the national turnaround when it comes.

"We are in a vicious cycle, but it's a cycle," said Stephen Levy, director of the Center for Continuing Study of the California Economy. "It's going to come back. There is a huge loss of wealth in portfolios. But we will build houses again and there will be foreign trade again and we will be spending money again."

In 2008, California lost 494,000 jobs, or 3.3 percent of its employment base. That was slightly worse than the national average of 2.7 percent. But California fared better than neighboring states of Arizona, Nevada and Oregon, and better than several other large states: Michigan, Florida, Ohio, North Carolina and Georgia. It did worse than New York, Massachusetts, Colorado and Texas, which was the only large state to add jobs last year.

Of the jobs lost here, 179,000 were in construction and finance, 111,000 were in retail trade, and 81,000 were in manufacturing. California lost 5.6 percent of its manufacturing jobs last year, but that was less, on a percentage basis, than the national average of nearly 8 percent. The state's fastest-growing and highest-paying job sector, professional and technical services, lost only 800 jobs last year.

These numbers suggest that some of the panic about California's business climate might be misplaced or at least exaggerated. Over the past decade, even after the debacle in 2008, California's share of national employment has not changed. The state accounted for 10.9 percent of nonfarm wage and salary jobs at the beginning of 2000 and the same in January 2009.

The state's share of national employment rose to a little more than 11 percent during the decade before falling back to where it started.

One reason the state's unemployment rate is so high is that an unusually large number of people – 310,000 – entered the work force in 2008 despite the recession. This is partly due to immigration and partly, perhaps, to people "unretiring" or spouses forced to work after one person in a couple lost a job or experienced a pay reduction. If California had experienced the same labor force growth as the nation in 2008, its unemployment rate would be a point lower, and if the state had seen zero growth in the labor force, the unemployment rate would have been 8.3 percent – still bad but not quite as ugly as the double-digit rate we are seeing now.

California will get through this. If state leaders focus on encouraging our strengths – higher education, innovation, entrepreneurship – and don't do too much long-term damage, the economy could emerge healthier than ever.