Residential Air Purifiers and the Value of Clean Air

(co-authored with Ashfaqul Chowdhury, Teevrat Garg and Maulik Jagnani)

Abstract

Valuing non-market amenities from purchases of durables that deliver them, like clean air from purifiers, requires an assumption about use intensity. Anticipated use is private; where operating costs suppress it below the assumed in-tensity, the inferred value is understated. Our use-based estimator prices clean air from how metered purifier use responds to randomized operating costs, un-correlated with the disutility of operation. In field experiments among middle-income households in Dhaka, where PM2.5 is ten times WHO guidelines and under 1% own a purifier, neither credit nor information raises demand, free purifiers are barely used, and most decline to run one even when paid forty times the operating cost. Even with the bias removed, marginal willingness to pay for the partial, in-home exposure reduction a purifier provides is near zero, its 95% upper bound below prior estimates. Operating one is costly: private defense fails at the operating margin, invisible to purchase data.