L.A. home prices appear to be in freefall, especially in luxury areas.

House prices in the Los Angeles Basin, on a three-year losing streak, may yet still be heading for the steep part of the slope.

The latest data available reveals a sudden drop in home prices, starting in the second half of 1992 and continuing, particularly at the high end of the price range.

"My conclusion is that house prices have fallen significantly in the past three years, and are continuing to fall," said Nelson Pedrozo, economic researcher with the UCLA Business Forecasting Project, who has been studying Los Angeles house prices.

House prices in Beverly Hills, Brentwood and the Palos Verdes Peninsula have receded all the way to below 1988 levels -- and look to be still free-falling.

Yet at latest read, February 1993, the median price on an existing, single-family detached home in Los Angeles County had fallen to $180,000, down "only" 14.3 percent from a peak of $210,000 in mid-1991, according to information provided by John Karevoll, publisher of the Southern California Real Estate Observer and financial editor at Dataquick Information Systems, a La Jolla-based real estate information service.

But the overall median figure is masking deeper declines, for three reasons: First, high-end homes are dropping deeply in value, but those drops are not reflected in the median price because the expensive homes remain above the mid-mark. Second, the median figure is not adjusted for inflation. And third, the median price is not adjusted to compensate for the size of the homes being sold.

Let's take a look at each of these three reasons in greater detail:

* On the first point, high-priced homes are indeed on a much steeper downward slope than homes priced closer to the median.

According to Dataquick, a median-priced home in Beverly Hills (zip code 90210) hit a peak of $1,485,000 in November 1990. But as of February 1993, that figure has slid to $780,000, a 47.5 percent plummet.

In Brentwood, the price as of February 1993 had tumbled by 34.7 percent from its June 1990 peak, and in the Palos Verdes Peninsula, by 31 percent from its June 1990 peak.

Homeowners in higher-priced parts of Los Angeles are acutely aware of the changing real estate markets -- which has led to the rash of anecdotal observations about plummeting home prices.

"I bought my home six years ago in Calabasas," said Roger Pondel, nameplate partner at the public relations firm Pondel, Parsons & Wilkinson. "We saw it about double in value in the next three, but now it is worth just a little bit more than what we paid for it."

Confirms publisher Karevoll, "The upper price ranges have been under severe pressure. Prices have fallen to below 1988 levels, and we still haven't hit the bottom."

But the higher-priced homes do not affect the reported median price for this reason: If large homes in better neighborhoods fall to, say, $350,000 from $650,000, they still are in the upper half of all home prices. The median is the point at which half of homes sell for less, and half for more.

It would take a fall in prices of typical homes -- those that sell for $165,000 to $200,000 -- to make a serious dent in the reported median price, according to real estate maven Karevoll.

And while that is perhaps beginning to happen, it hasn't happened in the big way that it has to expensive houses.

* On the second point, the downward slope of L.A. home prices becomes even steeper when prices are adjusted for inflation.

The reported median prices, as reported by Dataquick, are not adjusted for inflation. But since 1989, while house prices have been deflating, the general rate of inflation has plugged ahead at between 2.9 percent and 6.1 percent per year.

In 1989, the median-priced, single-family home in Los Angeles County sold for $200,000, compared with $180,000 in February of 1993. That's a drop of 10 percent, in nominal terms.

But since 1989, consumer prices have edged forward by 14.4 percent.

So when adjusted for inflation, that nominal 10 percent drop in the median price actually becomes nearly a 25 percent drop.

Even worse, the median price has been under pressure recently, meaning middle-market homes may soon also come under severe price pressure.

* On the third point, median prices do not compensate for the size of homes being sold.

In some periods, as when house prices and interest rates are high, often the only buyers are better-off people who buy larger homes. This tends to "pull up" the reported median price, even though "typical" home prices are not really moving. But at other times, if only low-end homes are selling, the reported medians and averages would be yanked down.

One way to partially compensate for biases in the size of homes being sold is to look at average home prices, on a per-square-foot basis.

The peak for house sale prices in Los Angeles County, as measured by dollars per square foot, was July of 1989, at $157.87.

The per-square-foot price declined only slightly, in nominal terms, until mid-1992 -- when, like expensive home prices, it began to fall more sharply.

By February, the average sales price of a home in Los Angeles County had fallen to $135.76 a square foot -- down 14 percent from the peak.

And after adjusting for inflation, the per-square-foot price in February had fallen 24.7 percent since July of 1989.

Moreover, the per-square-foot price has been sinking more rapidly in the last several months. The big question now, of course, is: Where is the bottom on house prices?

The answer, of course, depends on who is asked. Pedrozo of UCLA thinks there is more pressure on house prices to go down, in part because local prices are still about double the national average.