Leonardo Madio, Professeur d'économie à l'Université de Padoue

Jeudi 19 mars 2026, nous accueillons Leonardo Madio, Professeur d'économie à l'Université de Padoue.

Titre de sa présentation : Curation with moral hazard: Why platforms host low quality, article co-écrit avec Özlem Bedre-Defolie (EUI) et Bjørn Olav Johansen (Bergen).

Résumé : We identify a novel mechanism explaining why a revenue-maximizing platform tolerates low-quality sellers it can costlessly exclude. We model monopolistic sellers operating in independent markets: normal sellers differ in intrinsic quality and can raise it through costly, unobservable effort; bad sellers supply zero quality or harmful products (negative quality) and exert no effort. The platform operates a binary certification system and chooses whether to host bad sellers. Admitting some bad sellers thickens the left tail of the quality distribution, increasing pooling risk and thereby raising normal sellers’ effort (under certain conditions), but it also lowers average quality and trade value. We show that hosting bad sellers is optimal for the platform if these sellers are harmless or not too harmful. Relative to a social planner, the platform always over-tolerates bad sellers. Platform liability reduces the misalignment between private and social incentives, whereas other liability and consumer compensation schemes may be ineffective.

*with Özlem Bedre-Defolie (EUI) and Bjørn Olav Johansen (Bergen)*
 

Le séminaire a lieu à 13h30, au GAEL, en salle 227.