Turbines and property values
To the Editor:
A recent article talked about a large national study on residential property values in the vicinity of wind turbines. The study, with Ben Hoen from Lawrence/Berkeley Lab as principal author, found that there is no significant impact on property values. This 2012 study, however, as well as its 2009 predecessor, has numerous flaws and should not be used for policy-making.
Included in the study are homes within 10 miles of a wind facility, yet small rural counties were "cut out of the study" because there weren't enough sales. Furthermore, in at least the earlier study, less than 10% of sales transactions had a view of the turbines, and only about 2% had a view "greater than minor." Other data are also excluded, such as developer buyouts or resales at reduced prices. Such exclusions severely skew the results.
The researchers use sales data, which are not a true reflection of property value. For example, homes near turbines may be on the market for a long-enough time for the price to drop, often drastically. Michael McCann found that after 2 to 3 years on the market, homes suffered a 20% to 40% reduction in value.
Scientifically, the study doesn't bear up. First, it doesn't use established methods for the type of analysis employed (regression analysis).
The data, drawn from across the country, are not homogeneous, yet homogeneity is a basic assumption underlying regession analysis. For example, the authors used large ranges in such variables as the size, age, and location of the property or economics of the area. Other important property characteristics were omitted, such as number of bedrooms or presence of a garage.
The authors refuse to release the raw sales data, yet they claim that the paper was peer-reviewed. Without access to the underlying data, the reviewer cannot validate the conclusions, replicate the analysis, or test alternatives, which are all part of true scientific peer review.
Finally, the work was supported by the Department of Energy, an agency with a clear pro-wind bias. As one of my sources wrote, "a generously compensated pro-wind advocate is the least reliable source for independent, professional advice or 'expert' opinion publications upon which to base far reaching land use approval or policy decisions."
As an aside, another source described a conversation in which Dr. Hoen acknowledged that they really don't know what happens close to the turbines and suggested that if developers really believe that there is no impact to property values, they should guarantee it.
I have drawn from work by Michael McCann and Albert R. Wilson, both highly qualified real estate appraisers with expertise in appropriate methodologies for mass appraisals.