Private Adoption of Public Good Technologies: The Case of PurpleAir

We study the private adoption and diffusion of a technology that provides a local public good – PurpleAir (PA) pollution monitors. From a purely informational perspective, the ideal spacing of these monitors should reflect the degree of spatial correlation in pollution. In stark contrast, we find that monitor adoption is spatially highly clustered in less polluted areas, suggesting the marginal monitor adopted provides minimal additional public information. Moreover, monitor adoption mainly occurs in affluent, predominantly white neighborhoods, underscoring the potential environmental justice concerns associated with the private provision of this public good.