Housing prices in three markets Boston, San Diego and Ft. Lauderdale have increased to a level that cannot be sustained, according to a new economic yardstick designed to help builders, lenders and investors determine which parts of the country are overheated and in danger collapsing.

In addition, according to the Housing Cycle Barometer, 14 other markets are experiencing what Irvine, Calif.-based real estate consultant John Burns said are "small" housing price bubbles in relation to average incomes. Burns introduced the new index at the Pacific Coast Builder Conference in late June in San Francisco.

The California consultant's analysis is in line with that of most housing economists, who say that while price bubbles may crop up in a few housing markets, there is nothing to fear on a national basis. But he is the first to actually report which places are at the most risk.

On a scale of 1 to 10, Boston's situation was the most perilous. It rated a 9.3 on the housing price Richter scale. San Diego has a reading of 7.6; Ft. Lauderdale, 7.3

Burns said anything over 7.5 should be considered a "large housing bubble." But he also said that a collapse is not imminent in any particular market. In fact, he told the assembled builders not to be afraid to continue raising their prices.

At the same time, though, he suggested that ever-increasing prices cannot go on forever, and that eventually the bubble will burst.

"It won't happen tomorrow; I hope it won't happen for a while," the consultant said, noting that demographics, government emphasis on home ownership, constraints on new construction and strong employment growth all will serve to stave off any price correction for some time.

But when the end comes, he warned, the places with the greatest home price appreciation will take the longest to recover.

The barometer calculates two key ratios one between home prices and income levels and the other between annual mortgage payments and income. Then, the current ratios are compared to the mean ratio for the last 21 years in each area.

Of the 44 markets surveyed, 24 were not overpriced.

Surprisingly, San Francisco, which is generally considered the most over-priced housing market in the country, ranked only fourth on the housing cycle barometer with a 7.3 rating. Nearby San Jose was seventh at 6.9.

In another surprise, a number of relatively inexpensive places were ranked above 5.0, the point on the scale at which housing prices start to become inflated. Besides Ft. Lauderdale, which was in the 7.5 to 10.0 "large housing bubble" range, Miami, Tampa and Charleston, S.C., were in the "small" bubble category.

But Burns said his benchmark is "not a measure of expensive housing markets, but rather a measure of which markets are expensive in comparison to their own history."

MARKETS ON THE BUBBLE

Housing prices in 14 major markets throughout the country are out of whack in relation to household incomes and mortgage payments, according to industry consultant John Burns.

Boston	9.3
San Diego	7.8
Ft. Lauderdale	7.6
San Francisco	7.3
Miami	7.1
Denver	7.0
San Jose	6.9
Orange County, Calif.	6.6
Charleston, S.C.	6.5
New York	6.1
Tampa	5.9
Oakland, Calif.	5.9
Portland, Ore.	5.6
Minneapolis	5.4
Phoenix	5.4
Sacramento	5.3
Los Angeles	5.0

Source: John Burns Real Estate Consulting, Irvine California.