The Impact of Wind Power Projects on Residential Property Values ...

mile and outside <strong>of</strong> three miles <strong>of</strong> the turbines (x 1 ) are compared to the sales volume in that same
group in the one to three mile distance band (x 2 ). <strong>The</strong>se three tests help to evaluate whether sales
volumes are significantly different after wind facilities are announced and constructed, and
whether sales volumes near the turbines are affected differently than for those homes located
farther away. 101
7.3. Analysis <strong>of</strong> Results
Table 29 and Figure 11 above show the sales volumes in each PERIOD and DISTANCE
category, and can be interpreted as the percentage <strong>of</strong> homes that are available to sell that did sell
in each category, on an annual average basis. <strong>The</strong> sales volume between one and three miles and
before facility announcement is the lowest, at 1.8%, whereas the sales volumes for homes
located between three and five miles in both periods following construction are the highest, at
4.2%.
<strong>The</strong> difference between these two sales volumes can be explained, in part, by two distinct trends
that are immediately noticeable from the data presented in Figure 11. First, sales volumes in all
periods are highest for those homes located in the three to five mile distance band. Second, sales
volumes at virtually all distances are higher after wind facility announcement than they were
before announcement. 102
To test whether these apparent trends are borne out statistically the three sets <strong>of</strong> t-Tests described
earlier are performed, the results <strong>of</strong> which are shown in Table 30, Table 31, and Table 32. In
each table, the difference between the subject volume (x 1 ) and the reference volume (x 2 ) is listed
first, followed by the t statistic, and whether the statistic is significant at or above the 90% level
(“*”).
Table 30 shows that mean sales volumes in the post-announcement periods are consistently
greater than those in the pre-announcement period, and that those differences are statistically
significant in four out <strong>of</strong> the nine categories. For example, the post-construction sales volumes
for homes in the three to five mile distance band in the period less than two years after
construction (4.2%) and between three and four years after construction (4.2%) are significantly
greater than the pre-announcement volume <strong>of</strong> 2.3% (1.9%, t = 2.40; 1.9%, t = 2.31). Similarly,
the post-construction sales volumes between one and three miles are significantly greater than
the pre-announcement volume. <strong>The</strong>se statistically significant differences, it should be noted,
could be as much related to the low reference volume (i.e., sales volume in the period less than
101 An alternative method to this model would be to pool the homes that “did sell” with the homes “available to sell”
and construct a Discrete Choice Model where the dependent variable is zero (for “no sale”) or one (for “sale”) and
the independent variables would include various home characteristics and the categorical distance variables. This
would allow one to estimate the probability that a home sells dependent on distance from the wind facility. Because
home characteristics data for the homes “available to sell,” was not systematically collected it was not possible to
apply this method to the dataset.
102 It is not entirely clear why these trends exist. Volumes may be influenced upward in areas farther from the wind
turbines, where homes, in general, might be more densely sited and homogenous, both <strong>of</strong> which might be correlated
with greater home sales transactions. <strong>The</strong> converse might be true in more rural areas, nearer the wind turbines,
where homes may be more unique or homeowners less prone to move. <strong>The</strong> increasing sales volumes seen in periods
following construction, across all distance bands, may be driven by the housing bubble, when more transactions
were occurring in general.
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