Virtually all international organizations dedicate considerable resources to data gathering and the elaboration of specific policy recommendations. A case in point is provided by the air quality guidelines published by the World Health Organization (WHO) since 1987. In theory, the likelihood of adopting the WHO recommendations for the definition of air quality standards should be high throughout all jurisdictions since this source spares them from carrying out costly scientific studies and indicates a certain level of effectiveness in reducing air-related health problems. In Latin America, however, there is remarkable variation concerning the adoption of the WHO recommendations. This paper addresses these differences in the adoption patterns of Latin American countries. Which countries refuse to follow the WHO recommendations? What explains the variation in the setting of air quality standards in the region? These are the main research questions guiding this analysis. To effectively address them, this paper develops an explanatory model based on the literature on transnational policy diffusion, which is tested by an innovative dataset on air quality standards in 17 Latin American countries observed throughout the period from 1986 to 2010. The findings of the quantitative analysis will show that economic factors are particularly decisive for explaining the diffusion of WHO air quality standards in Latin America.
