Notwithstanding an initial review of the MPAC report Abstract and policy support statements, when you look a little deeper and see the sale and assessed values displayed on D2, it appears the raw sale prices for the whole study are about 25% lower values within 1km vs. > 5km. In fact, the graph confirms that impacts are significant out to at least 5km (3 miles).
Based on D2, it would also appear they (MPAC) are in a good position to defend that they have generally not overvalued homes near turbines, since the Current Value Assessments (CVA) are consistent with time adjusted actual sale prices. But their opinion of no (statistically significant) impact near vs. far is at war with the factual sale price proximity trends found in the study.
Further, for environmental impairment analysis, the IAAO Standards discourage regression and instead recommend use of paired sales methodology, with direct, detailed comparisons of individual sale data, near and far from the environmental disamenity in question. They heavily cite the IAAO, as is appropriate, but seemed to have missed that most relevant standard regarding use of regression and limitations for exactly this kind of analysis.
As copied below the D2 bar chart, and found buried way back in Exhibit E, is an important conclusion. MPAC internally, directly contradict the Abstract opinion they have expressed on wind turbine impacts.
Many of the regression studies keep showing roughly 25% lower values near turbines when the raw data is sorted by distance, yet the statistical significance ends up indicating to the authors no impact on value. Perhaps they should consider use of recognized appraisal methodology for measuring proximity impacts from turbines.
Michael S. McCann
McCann Appraisal, LLC