Matt Twitters to wonder why I didn’t blog the Post’s annual housing review, which offers ZIP code level detail for home sales and prices in the metropolitan area. I didn’t know it was out! But his analysis strikes me as pretty much on point:

Alejandro Lazo writes about the decline in home prices in the Washington, DC metro area in 2008, writing that “By any measure, 2008 was a brutal year for the local real estate market, as gains made during the housing boom continued to unravel.” Except it actually wasn’t so brutal in the District itself where prices went up. Ken Baidfeld offers this chart and hypothesizes that “strong central cities” may be weathering the housing bust better than sprawling exurbs…I think this is probably correct in broad terms. Housing overcapacity, almost by definition, exists on the far-flung fringes of metro areas. On the other hand, the ZIP-by-ZIP analysis of changes in the District doesn’t show a particularly clear pattern.

A couple of things stand out to me. One is the broad trend that Ken and Matt both point out — home prices in the center generally held up much better than home prices in the exurbs. One reason for this is the greater elasticity of supply on the edge of the metropolitan area. Another is that exurban homeowners are more vulnerable to shifts in the cost of gasoline, which notably spiked in price last year. Another is that the exurban economies were more dependent on housing construction, so the decline in prices was amplified by shrinkage in a local growth industry. And another is that wealth generally declines as you go out, and the wealthy are better able to weather a recession without, say, defaulting on their mortgage. I’m sure there are other factors, as well.

Another thing I found interesting was the strength in condo prices, even in the center and inner suburbs where a lot whole of them have been built in recent years. Sure, some developers may be sitting on a lot of empty units with high price tags, and others have switched units to rentals, but there is still surprising strength there.

And another thing is how funny it is to think about the dynamics of the housing market in 2008. I mean, in the second quarter, economic activity was surprisingly strong while gas prices were through the roof. In teh fourth quarter, gas prices were plummeting as the national economy was rapidly contracting. And in between there was a rather epic credit crunch. I suspect that if you compared the first half of the year to the second you’d see a very different picture. Or maybe not. What you’d probably see is the above trends amplified in the first half, and then diminished in the second as everything started heading down. This year should be the reverse, with everything looking awful for the first half of the year and with disparities reasserting themselves as recovery begins.

One other thing — Matt notes that ZIP level data in the District doesn’t show a clear pattern. That’s true, but I wouldn’t make too much of it. The sample sizes are too small, and small changes in the neighborhood can have big effects. The most interesting bit is that most ZIPs had a fairly small change up or down, which shows the strength of the District market — so far, at least.