The most recent Anderson Forecast from UCLA has a distinct R&B vibe: R, as in recession for the national economy, and B for bubble in California's gravity-defying residential real estate market.

The University of California, Los Angeles' economists are in familiar territory here, having first raised the R word in their December quarterly forecast and the notion of a housing bubble last summer.

There is concern about the latter because forecasters note that rough estimates have California's housing stock increasing in value by about $400 billion annually per year over the past four years.

Neither economic eventuality can be put in sharp focus, though.

UCLA forecasters know a recession is coming, just not when. Nor do they know how loud a pop the bubble will make when it breaks.

Since the economy is cyclical, recessions follow good economic times, which by most accounts we are experiencing now. And while there can be a lot of talk about recession, we don't know if we've been in one until it has come and gone.

That word always comes from the National Bureau of Economic Research, a private, nonprofit, nonpartisan organization that tracks the economy's peaks and valleys. It defines a recession as a significant decline in economic activity spread across the economy, lasting more than a few months, and visible in real gross domestic product, real income, employment, industrial production and wholesale-retail sales.

It's much broader, and more complicated, than the classic definition of two consecutive quarters of GPD decline that usually surfaces in news accounts.

Dealing with a housing bubble can be just as cumbersome.

"We're in a very strange place right now," said UCLA senior economist Christopher Thornberg, who does the California outlook. "Right now, for the very first time that I know of, we have a labor market that's basically one year into recession and a housing market that's in the 12th year of its cycle. Usually they move together."

Consider this. Over the past 12 years, from February 1994 to last month, the median price of a previously owned home in the San Fernando Valley soared 177.7 percent to $500,000.

Annual appreciation gains of 20 percent or more have been the norm for months on end, though there is some narrowing on the horizon.

"The housing market has been outrunning the fundamentals for two years now," said economist Daniel Blake, director of the San Fernando Valley Economic Research Center at California State University, Northridge.

Something obviously has to give. But neither he nor Thornberg are expecting a price collapse unless something really bad happens to the economy.

Buyers today are jumping into the market on the expectation of future gains even though prices are near record highs in the Valley and, by one account, at record levels in Los Angeles County.

Prices did deflate after the end of the last big bull housing market in the late 1980s.

During that run, the median price of a Valley house peaked at $245,000 in late 1988, then lost 36.7 percent of its value before hitting bottom at $155,000 exactly six years later.

Several things were different then. The nation's economy went into a recession from the July 1990 third quarter to March 1991 first quarter.

But the impact was greater in California because the powerful aerospace sector experienced a severe downsizing, jobs were lost and a powerful earthquake caused severe property damage in the Valley.

Thornberg says even economists can't time bubbles.

And prices are now ahead of the curve, in part because demand continues to outstrip supply. The market has not been overbuilt, interest rates are still low, but expected to move up, and credit is still readily available.

Something is sure to spark a price turn, possibly increased use of interest-only, no-down-payment or adjustable loans.

"I doubt you'll see a big price collapse," Thornberg said. "But maybe stagnant prices for five to six years."