IF AMERICA'S economy avoids sliding from downturn into a full-
blown recession, it will be because the consumer continues to
spend freely. Some economists had feared that this week's
revised GDP figures would show that the economy had shrunk in
the second quarter. Instead, consumer spending kept the figure
positive—albeit at just 0.2% compared with the previous quarter
at an annual rate.  Consumer spending, which accounts for two-
thirds of economic activity, has remained strong despite falling
share prices and rising unemployment for one main reason: a
housing boom. Average house prices rose 8.8% in the year to
March. New government figures, due this weekend, should still
show an upward trend.  True, house prices have softened in areas
most exposed to the “new economy” (remember that?), such as
Silicon Valley, San Francisco and New York. There has also been
a drop at the other end of the market: defaults on mortages on
mobile homes have risen sharply. But, strange though it may
seem, neither Manhattan apartmen