More heads need more roofs

   

Housing has become scarcer in the dark-colored states on the above map, with new residents moving in (or being born) faster than contractors can put up houses. (Click the map for a larger image, and download this file for complete data: Download housing_estimates_by_state_2006.xls ) The most extreme case is Alaska, which has grown by 42,520 people since 2000 but has only 15,182 more houses and apartments to accommodate them. Things are getting almost as tight in California, which has 2.4 million more people but only 900,000 new houses. And Connecticut has had slow population growth (only 92,270, or 2.7 percent more people since 2000), but it still hasn’t added half as many units to its housing supply. Will a shortage lead to higher home prices there?

In 11 states with sluggish population growth — including Massachusetts, Michigan, and Pennsylvania — the creation of new housing units has outstripped the creation of new residents. (North Dakota created 18,000 new homes even though it suffered a net loss of 5,000 people, and Louisiana is the only state to lose both homes and people.) Will there be a housing glut, and lower prices, in these states? Maybe, but if they can attract new employers who need new workers, those "extra" houses could suddenly become essential.

An environmentally conscious person might wonder why one new home for every two people isn’t good enough for economic development. But the average household size in America is getting smaller and smaller (down to 2.7 people at last count), thanks to our habits of marrying earlier, having fewer children, and refusing to die at the same time as our spouses.