Solar panel envy

Keeping up with the environmentalist Joneses.

Solar panel systems are expensive—averaging $35,000 before tax incentives—and green, marketed as part of the fight against climate change. But judging from a recent study, being wealthy and politically liberal means less to buyers than keeping up with the neighbors.

The study, conducted by Kenneth Gillingham of Yale and Marcello Graziano of the University of Connecticut, used data from Connecticut’s Clean Energy Finance and Investment Authority to map out 3,833 residential solar photovoltaic systems installed in Connecticut from 2005 to 2013, tying each system to a local population grouping as identified by the US census. Their results, published in the Journal of Economic Geography in August 2014, indicated that those who had neighbors with residential solar panels were significantly more likely to purchase solar panels themselves. In fact, the installation of one additional solar panel system in a one-year time period increased the average number of solar panels in a half-mile radius by nearly one additional system.

Gillingham attributes this pattern to both social learning and a phenomenon known as “observability”—or “green envy” in this case: “You observe others buying a Prius or putting up a solar panel, and if you have that as part of your identity as well, you’ll be more inclined to do those things too.” He says the results of this study are consistent with similar work conducted in California, but notes that he was still surprised at how powerful proximity proved to be.

“I expected income to be a stronger force than it turned out to be, but what we see in the data is that many middle-income and upper middle class do just as well” at going solar “as wealthy or very wealthy communities,” he says.

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