Why your neighbors installing solar panels matters more than subsidies

Fitting a decade of residential solar installation data from Catalonia to a logistic growth model, the authors find that peer imitation—not government policy or household wealth—is the dominant force shaping adoption. Social perception outweighs regulatory and socioeconomic variables when tested independently, and adoption clusters spatially along demographic lines. The upshot for policymakers: seeding visible installations in well-connected communities may accelerate the energy transition faster than subsidies alone.