Présentation de Adrien NGUYEN-HUU - CEE-M, Montpellier
**Abstract:** We assess the impact of signed environmental externalities on individual portfolio decisions in a lab-in-the-field experiment on finance professionals and students. Participants are prone to accept lower returns for positive environmental impact but will not bear increased risk. They show asymmetric pro-environmental preferences depending on the sign of the externality. Finance professionals are more pro-environment than students, particularly regarding positive externalities, and less influenced by a ranking signal about environmental performance. Control tasks show that experimental measures of pro-social and environmental preferences are significant predictors for students, while actual market practices for professionals explain a significant part of professionals portfolio composition. In addition, we propose an attempt to estimate a structural model of demand based on nested CES utility in order to profile individuals in terms of substittion-complementarity of decision factors (risk, return, externality). This is joint work with S. Duchêne, M. Willinger and D. Dubois.