Emisonian: Joe Emison's Blog

biz | tech | psych | law

Monthly Archives: January 2011

The Next Generation of AVMs

A version of this post appeared in the February 2011 edition of Live Valuation Magazine and is also available for download as a PDF.

“The most accurate way to value a property is to find out how much someone will pay for it. Unfortunately, sales data is only updated when a home sells. However, building permit data allows us to take property sale values and bring them up to date, thus giving us a newer, better way to value properties.”—Holly Tachovsky, president of BuildFax, a national aggregator of building permit data.

Most automated valuation models (AVMs) estimate property values by looking at the internal characteristics of properties as part of a “hedonic model,” and by looking at historic sales around the properties as part of a “repeat sales index.” In theory, the combination of the hedonic and repeat sales evaluations captures the full range of factors necessary to value a property automatically. In practice, the quality of the data that drives the hedonic model leads to imperfect results. This article describes a better type of AVM using building permit data.

  Read more of this post