Houses built on sand
Sep 13th 2007
From The Economist print edition

America's housing boom was almost modest by global standards—which is worrying


EVERYTHING in America is bigger. Cars, hotel rooms, servings at dinner, the salaries of sports stars and chief executives. So anything that merits the adjective “jumbo” is extravagantly large. Except, that is, for shrimp and home loans. In America a jumbo mortgage is one that exceeds the authorised limit for loans bought and securitised by Fannie Mae and Freddie Mac, the government-sponsored lenders. That cap was increased this year, to $417,000—a sum that, at today's exchange rates and prices, is barely enough to buy a cramped flat in the outer suburbs of London. Could it be that America's housing boom, which has now turned horribly sour, was not even super-sized?

That is what The Economist's table of house-price indicators shows (below). The S&P/Case-Shiller national index, the best gauge of American house prices, peaked last year after rising by 134% in the previous decade. France, Sweden and Denmark have all had booms of similar size. In Britain, Australia, Spain and Ireland, the ten-year increase in house prices has been even larger. If America is staring at a nasty housing crash, what does this say about the fate of frothy markets elsewhere?

Research by David Miles and Vladimir Pillonca of Morgan Stanley concludes that there are likelier candidates than America for a housing bust. In a recent paper covering 13 European countries as well as America, they assess how much of the rise in property values in the past decade can be put down to bubble-like optimism about future price increases. The authors constructed a model in which housing demand is driven by rising real incomes, population growth and declines in real interest rates. They then estimated the downward effect on prices from increased homebuilding. They argued that what is left—the part of price rises that is unexplained—is without substance and vulnerable to a correction.

In six countries—Belgium, Britain, Denmark, Greece, Spain and Sweden—real house prices have risen much faster than the model predicts. Mr Miles admits that calculation of real interest rates may have distorted the results for Greece. But in the remaining five countries, the average “excess” increase in real house prices is 47%. Some of the paper's results challenge accepted wisdom. Ireland's housing boom, often seen as a spectacular bubble, is almost entirely explained away by rapid real-income growth, rising population and the drop in real interest rates. Nevertheless, Irish house prices are now falling, if modestly.

The other surprise is America. The Morgan Stanley economists reckon the housing boom more or less reflected durable shifts such as rising incomes and population growth. That conclusion, however, hinges on the choice of price index. The authors' gauge of real house-price gains uses the series of the Office of Federal Housing Enterprise Oversight (OFHEO). That index excludes deals above the loan cap of $417,000, where price gains have been greatest, as well as transactions financed by subprime mortgages, where activity was most frenetic. Mr Miles says that using the Case-Shiller index, the assessment is gloomier.

Why America?
Even so, the contrast with events on the other side of the Atlantic is puzzling. Several of Europe's housing markets are more overpriced, but have lost only a little of their fizz in the past year. Price rises in Britain have even accelerated. If America's housing market was less puffed up, why is it alone bursting?

One reason is that America is a big country. Comparing its entire housing market—including slow-growing rural areas—with selected European hotspots makes it look less bubbly. In America's top-ten cities, for example, prices are up 171% in the past ten years, much more than the national average.

But what sets America apart is the time-bomb laid by subprime mortgage lending in the late stages of the housing boom. The way many of these deals were structured—two or three years of low “teaser” rates, which then switch to much higher tariffs—gave homebuyers with tarnished credit records a free option on house prices. If prices are expected to rise enough, borrowers may be willing to pay higher interest charges in order to keep the equity gains. If prices fall short of their hopes, borrowers have an incentive to default.

In short, dangerously loose lending standards fuelled America's housing boom and now the fallout from increasing defaults is exacerbating the bust. Nearly 15% of subprime borrowers are behind with their mortgage payments. The defaults so far have poisoned the mortgage market for prime borrowers too.

The Federal Deposit Insurance Corp, which guarantees bank deposits in America, reckons over 1.5m households will eventually be unable to meet their mortgage payments. Prices are falling and more forced sales will add to the already swollen stocks of unsold homes.

What might this presage for Europe's overpriced markets? Robert Shiller, a seasoned bubble-hunter at Yale University, has stressed the role of news reporting in influencing price expectations. If America's slump deepens, it might trigger a reassessment in Europe's property hotspots, particularly as tighter credit markets start to price out the more speculative investor.

Asset markets are unpredictable. When house prices in London stalled during 2004-05, many pundits thought the spell had been broken. Then the upward trend mysteriously reappeared. As Mr Shiller noted recently: “The London case study should caution any who feel that a substantial decline in home prices in the US is inevitable.” No one knows for sure how markets in Europe might respond to events in America. But one thing is certain: when it comes to asset bubbles, bigger is not better.

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