The South Tahoe Realty Blog

The South Tahoe Association of Realtors (STAoR) staff went to a C.A.R. conference last week. Thus, they didn’t publish May market statistics until today. Honestly, I got impatient a few days ago and started mining our MLS for data. I had no idea what I was in for!

Two days, six phone calls, and five hours of data mining later, I have just a few nuggets for you. I’ll give you the biggest nugget first: The monthly median sold price that STAoR presents to us isn’t actually the median for that specific month. It is the median for the past twelve months. To clarify, STAoR gave us a median sales price of $428,000 for April 2008. I searched our MLS and found the following:

Median sales price for homes sold 4/1/08 to 4/30/08 - $379,000
Median sales price for homes sold 4/30/07 to 4/30/08 - $428,000

In fact, here’s a good bit of the data that I overturned:

Before I continue, I’ll relay a couple things told to me by STAoR staff over the last two days. First, they are not the only ones who present data in this manner. They say that many boards in small markets do the same thing. There is good reason for this. It smoothes data and eliminates variance. With few homes being sold monthly in small markets like South Lake Tahoe, there can be spikes or depressions in the data that don’t accurately reflect the market. For instance, let’s say sixteen homes will be sold in June 2008 (extremely unlikely, but it happened in January and February). If nine of these homes are closed at over one million dollars, the median will be over one million, which is more than double the actual median value of South Lake Tahoe homes. STAoR eliminates variance by incorporating a larger data set.

They aren’t truly presenting a median sales price, however. Their statistic is more like the 50-day moving average that stock market analysts use. In fact, I call their stat a 12-month moving median. There are two problems with it: 1) It does not reflect what actually happened in a month; and 2) its data centers on a date half a year in the past. Check out the table. The 12-month moving median peaks in March and April of 2006. However, the market really peaked seven months earlier in August 2005. If someone was basing a decision to sell a few years ago on this set of data, they would have been seven months late and more than a few dollars short! In the same breath, when the market bottoms out, the 12-month moving median won’t reflect this until half a year later. It is in cases like this that the actual median is much more helpful in decision making.

I’ll be posting more reflections on my data mining in the next few days.

Tags: median, south tahoe association of realtors, staor, Statistics

This entry was posted on Wednesday, June 11th, 2008 at 4:08 pm and is filed under Statistics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.