This paper analyses a second-order polynomial spatial structure in the residues of a regression model. We propose a new specification that captures spatial dependence on two different levels, adding a new autoregressive cycle to the errors of the classical spatial error model (SEM). The...

Air quality is one of the major concerns in big cities. It is therefore of interest to evaluate properly air pollution. Specifically, this paper aims at measuring how air quality is incorporated in transaction prices in downtown Madrid. For that purpose, we use multilevel models since our sample...