I receive a weekly housing market report from Altos Research LLC. One of the interesting tables of data contained in the report is a Quartiles table for the current inventory (Active Listings). This table offers a different perspective on the data, instead presenting a single median number for the entire market.
I took the quartiles concept and applied it to recent solds rather than current listings. As I do for my monthly medians post, I looked at July sales data for Site/Stick Built properties only, sold in Reno and Sparks, Nevada (MLS area #100).
The quartile breakouts can be found in the table below. Let me know your thoughts on this presentation of data by quartile. Like? Dislike? Does it add any value? Thanks.
| Quartile | Median Sold Price | Sq. Ft. | Age (years) |
|---|---|---|---|
| Top/First | $300,000 | 2,881 | 6 |
| Upper/Second | $174,000 | 1,999 | 11 |
| Lower/Third | $130,000 | 1,560 | 21 |
| Bottom/Fourth | $87,000 | 1,160 | 48 |
Note: The median home price data reported above covers the cities of Reno, Nevada and Sparks, Nevada [NNRMLS Area #100]. Residential data includes Site/Stick Built properties only. Data excludes Condo/Townhouse, Manufactured/Modular and Shared Ownership properties. Data courtesy of the Northern Nevada Regional MLS – August 2011. Note: This information is deemed reliable, but not guaranteed.
Anonymous Coward
I like the idea, and think it’s more valuable than just the usual “median” reporting that shows up every month.
But I’m confused because I don’t know what the numbers are. When I think “quartiles”, I think three numbers, at the 25% percentile point, the 50% percentile point, and the 75% percentile point, dividing the sales up into four equal groups. I see 4 numbers. Are they the 20/40/60/80% numbers? If so, that’s cool too (and perhaps even preferable to quartiles), but you might want to specify what the numbers are.
Mark Twain
“Lies, damned lies, and statistics”
Guy Johnson
Anonymous Coward, Thank you for your feedback. The four groups are:
Most expensive 25% of properties
Upper-middle 25% of properties
Lower-middle 25% of properties
Least expensive 25% of properties
The median numbers are the median of each group. Perhaps I’ve used the term “quartile” incorrectly.
MikeZ
So …with 490 sales for July, the quartiles above each contain 122 or 123 sales?
Are the Sq. Ft. and Age values averages or medians?
Guy, if you want to provide a more complete representation of one month’s sales data for readers to pick at, consider a histogram with ~100 bins.
Anonymous Coward
Guy Johnson: Groovy. Thanks for the clarification. My guess was pretty far off, but rereading the original article, it should have been obvious those were the medians of the four quartiles, rather than the “breakpoints”.
Although MikeZ’s request would also be nice, I think those four numbers (at the 12.5, 37.5, 62.5, and 87.5 percentile points) give a pretty nice picture of where the market is. The one surprise (to me) is the strong correlation of age with quartile.
Guy Johnson
MikeZ, yes each quartile contain 122-123 sales. And the square foot and age numbers are medians. Thanks for the suggestion to produce a histogram.