• Les règles de vote multi gagnants : Une proximité axiomatique est-elle liée à des résultats similaires ? Marin Gohard

Résumé :
Les règles de votes multi gagnants ont de multiples applications (1er tour d'élection, concours de différentes sortes, choix de produits à promouvoir pour une entreprise...). Elles sont cependant moins étudiées que les règles qui n'élisent qu'un gagnant. En partant de l'étude axiomatique de certaines de ces règles, nous nous sommes interrogés sur la similarité des résultats entre ces règles. Ce travail porte sur une catégorie de règles multi gagnants appelées les committee scoring rules et la fréquence avec laquelle ces règles donnent les mêmes résultats. Pour cela nous menons des simulations d'élections en faisant varier le nombre de candidats et de votants. Nous aborderons aussi le temps de réponse du programme notamment lorsque le nombre de votants et/ou le nombre de candidats augmente.

• Evaluation of the size of anaerobic digestion units on real estate prices in the French Grand Ouest (Brittany and Normandy regions) Martin Faulques, co-écrit avec J. Bonnet et S. Bourdin

Abstract:
The impact of the price of real estate is one of the crucial points on the questions of social acceptability that face the installations of anaerobic digestion units in France. To date, only three studies have been conducted on the price of real estate, three of them at the international level. MODICA's (2017) analyses the impact of biogas plants on average property values by municipality based on revealed preference data in Piedmont, Italy, and finds no evidence of impact. However, PECHROVA and LOHR (2016) find a negative impact of biogas plants on house prices based on eight biogas plants in the Jihomoravsky region of the Czech Republic using the hedonic pricing method. As for the study conducted by ZEMO et AL. (2019), they highlight that only large-scale farms and biogas facilities have a negative effect on property values, while small-scale facilities have a positive effect. More importantly, the acceptability of biogas facilities can vary from country to country (SCHULACHER AND SCHULTMANN, 2017) and even from region to region within a country (KORTSCH et AL., 2015). Given the very limited number of economic evaluation studies of residents' opposition and support for facilities and the inconclusive results, it is important to obtain more evidence on the effects of biogas projects on the hypothetical decrease in housing prices and its influence on social acceptability. On a database composed of 61,942 sales between 2015 and 2021 on real estate sales in the French Great West (Normandy and Brittany regions), a difference-in-difference (DiD) type counterfactual method is used to evaluate the effects of anaerobic digestion units on the price of real estate in areas near these units. This study aims to continue the work initiated by ZEMO et AL. (2019) by applying a new field of study (Normandy and Brittany) and making changes to the method (DiD). The comparison will also examine the impact of social opposition on real estate prices by identifying all units that were subject to social opposition before and after their installation.