This special issue of Investigaciones Regionales is published in memory of Professors Jesús Mur and Ana Angulo, both faculty members of the Department of Economic Analysis at the University of Zaragoza. Their research made a decisive contribution to consolidating spatial econometrics within regional science, with a sustained emphasis—both methodological and empirical—on the importance of model specification and selection when incorporating spatial structure. As a tribute, the issue includes the re-publication (with permission) of their paper “Model selection strategies in a spatial setting: Some additional results”, originally published in Regional Science and Urban Economics (2009), which remains an indispensable reference in the literature. The remaining articles extend this legacy from complementary perspectives. Taken as a whole, the monograph highlights the continued relevance of Mur and Angulo’s central message: when space is part of the data-generating mechanism, reliable inference requires taking specification strategy seriously.