Department of Numbers

4Q Sales Reports

Posted Wednesday, January 06 2010

The major brokerages in the city released their 4Q reports yesterday. It would have been neat if Department of Numbers sales data had come out on the same day (or the day before), but it was not to be. didn't release last month's data until this morning. Ah well, Department of Numbers still publishes two monthly updates in between these quarterly reports and we cover far more geography. I think that's real value.

So how does Department of Numbers data compare to the brokerage data? Quite well I'd say. Curbed highlighted the comparables for Manhattan yesterday in their State o' the Market post. Here's the summary.

Manhattan's 4Q 2009 Median Sales Prices

Reported byManhattan 4Q 2009
Median Sales Price
Department of Numbers$775,000

Since I'm tracking monthly sales prices in Manhattan I had to compute that 4Q median manually — not by hand or anything; I use R. In addition to the 12 month rolling sales prices, I'm thinking I should maybe add a 3 month (i.e. quarterly) rolling median so that these comparisons are easier to make. I think that the monthly DoN numbers are quite valuable, arguably more valuable than quarterly data, but people are naturally going to want to make comparisons with the big brokers even if their metrics are less frequently published. So I'll throw that on the todo list.

Finally, I'm in the middle of working on a tweak to the methodology that I think will get a few more house sales into my calculations. I don't expect it to change things much overall, but I'm hoping it will improve the metrics for houses in Manhattan a little. I hope to finish that up in the next couple of days. If it looks good I'll integrate it into the site soon after and write up a post on the change.