The latest data on growth suggest that the economy may again be faltering, just when President Bush desperately needs good numbers to make the case for his re-election. As bad as the Bush economic record is, it would be far worse if not for the growth of an unsustainable housing bubble through the three and a half years of the Bush Administration.

The housing market has supported the economy both directly–through construction of new homes and purchases of existing homes–and indirectly, by allowing families to borrow against the increased value of their homes. Housing construction is up more than 17 percent from its level at the end of the recession. Purchases of existing homes hit a record of 6.1 million in 2003, more than 500,000 above the previous record set in 2002. Each home purchase is accompanied by thousands of dollars of closing costs, plus thousands more spent on furniture and remodeling.

The indirect impact of the housing bubble is at least as important. Mortgage debt rose by an incredible $2.3 trillion between 2000 and 2003. This borrowing has sustained consumption growth in an environment in which firms have been shedding jobs and cutting back hours, and real wage growth has fallen to zero, although the gains from this elixir are starting to fade with a recent rise in mortgage rates and many families are running out of equity to tap.

The red-hot housing market has forced up home prices nationwide by 35 percent after adjusting for inflation. There is no precedent for this sort of increase in home prices. Historically, home prices have moved at roughly the same pace as the overall rate of inflation. While the bubble has not affected every housing market–in large parts of the country home prices have remained pretty much even with inflation–in the bubble areas, primarily on the two coasts, home prices have exceeded the overall rate of inflation by 60 percentage points or more.

The housing enthusiasts, led by Alan Greenspan, insist that the run-up is not a bubble, but rather reflects fundamental factors in the demand for housing. They cite several factors that could explain the price surge: a limited supply of urban land, immigration increasing the demand for housing, environmental restrictions on building, and rising family income leading to increased demand for housing.

A quick examination shows that none of these explanations holds water. Land is always in limited supply; that fact never led to such a widespread run-up in home prices in the past. Immigration didn’t just begin in the late nineties. Also, most recent immigrants are low-wage workers. They are not in the market for the $500,000 homes that middle-class families now occupy in bubble-inflated markets. Furthermore, the demographic impact of recent immigration rates pales compared to the impact of baby boomers first forming their first households in the late seventies and eighties. And that did not lead to a comparable boom in home prices.

Environmental restrictions on building, moreover, didn’t begin in the late nineties. In fact, in light of the election of the Gingrich Congress in 1994 and subsequent Republican dominance of many state houses, it’s unlikely that these restrictions suddenly became more severe at the end of the decade. And the income growth at the end of the nineties, while healthy, was only mediocre compared to the growth seen over the period from 1951 to 1973. In any event, this income growth has petered out in the last two years.

The final blow to the argument of the housing enthusiasts is the recent trend in rents. Rental prices did originally follow sale prices upward, although not nearly as fast. However, in the last two years, the pace of rental price increases has slowed under the pressure of record high vacancy rates. In some bubble areas, like Seattle and San Francisco, rents are actually falling. No one can produce an explanation as to how fundamental factors can lead to a run-up in home sale prices, but not rents.

At the end of the day, housing can be viewed like Internet stocks on the NASDAQ. A run-up in prices eventually attracts more supply. This takes the form of IPOs on the NASDAQ, and new homes in the housing market. Eventually, there are not enough people to sustain demand, and prices plunge.

The crash of the housing market will not be pretty. It is virtually certain to lead to a second dip to the recession. Even worse, millions of families will see the bulk of their savings disappear as homes in some of the bubble areas lose 30 percent, or more, of their value. Foreclosures, which are already at near record highs, will almost certainly soar to new peaks. This has happened before in regional markets that had severe housing bubbles, most notably in Colorado and Texas after the collapse of oil prices in the early eighties. However, this time the bubble markets are more the rule than the exception, infecting most of real estate markets on both coasts, as well as many local markets in the center of the country.

In this context, it’s especially disturbing that the Bush administration has announced that it is cutting back Section 8 housing vouchers, which provide rental assistance to low income families, while easing restrictions on mortgage loans. Low-income families will now be able to get subsidized mortgage loans through the Federal Housing Administration that are equal to 103 percent of the purchase price of a home. Home ownership can sometimes be a ticket to the middle class, but buying homes at bubble-inflated prices may saddle hundreds of thousands of poor families with an unmanageable debt burden.

As with the stock bubble, the big question in the housing bubble is when it will burst. No one can give a definitive answer to that one, but Alan Greenspan seems determined to ensure that it will be after November. Instead of warning prospective homebuyers of the risk of buying housing in a bubble-inflated market, Greenspan gave Congressional testimony in the summer of 2002 arguing that there is no such bubble. This is comparable to his issuing a “buy” recommendation for the NASDAQ at the beginning of 1999. More recently, Greenspan has done everything in his power to keep mortgage rates as low as possible, at one point even offering markets the hope that the Fed would take the extraordinary measure of directly buying long-term Treasury bonds. The man who testified that the Bush tax cuts were a good idea apparently has one last job to perform for the President.