On the Earth Week topic of Pollution, two Latin American Economic Review (LAER) articles make illuminating contributions. In “Do Mexicans care about air pollution?” (23:9), José Iván Rodríguez-Sánchez uses his economist’s toolkit – a residential sorting model, avoiding “the bias obtained by the traditional hedonic approach” – to quantify exactly how much residents of Mexico City are willing to pay (WTP) to improve their air quality. And in “Impact of environment and social attitudes, and family concerns on willingness to pay for improved air quality,” (25:7), Massimo Filippini and Adán L. Martínez-Cruz examine this same city’s residents’ WTP for pollution-alleviation measures “by means of a single-bounded, referendum format contingent valuation.” Lessening pollution in a place like Mexico City is a complicated undertaking; with these findings in hand, policy-makers can perform cost-benefit analyses with deeper understanding of what will work on the ground – and in the air.