That's called "smart growth." What is smart about it is another question.

An international study of 26 urban areas with "severely unaffordable" housing found 23 of those 26 subject to strong "smart growth" policies. What is "smart" about causing skyrocketing housing prices by making it illegal to build anything on vast amounts of land?

It is smart if you already own a home and the astronomical costs of buying or renting are going to have to be paid by other people who move into the area. It may be especially smart if restrictions on building cause the value of the home you already own to go up by leaps and bounds.

The San Francisco Bay area already has housing prices about three times the national average. The heavy burden that this places on people is reflected in the fact that two-thirds of the purchases of homes last year were financed with risky "interest-only" loans.

That means that the mortgage payments for the first few years do not reduce the amount owed by one cent. Moreover, since these are usually adjustable-rate mortgages, the payments can shoot up as the Federal Reserve raises interest rates.

The connection between severe restrictions on building and skyrocketing housing prices can be seen from evidence around the country and around the world, wherever people have succumbed to rhetoric about "smart growth" and sneers at "urban sprawl."

Severe restrictions on building began in the Bay Area back in the 1970s. At the beginning of that decade, housing in this area was as affordable as in other parts of the country.

A median income family in the Bay Area could pay off the mortgage on a median-priced house in just 13 years, using just one-fourth of their income. A decade later, it took 40 percent of their income to pay off the mortgage in 30 years. Today it requires 50 percent. Very "smart."