Trust on one market, robustness on the other: understanding the coexistence of decentralized and centralized markets

Résumé En

Centralized markets are often considered as being more efficient thanbilateral exchanges, based on the fact that information is uniformlyspread among all the agents. However, the influence of trust onthe outcome of decentralized markets has been underlined by manyauthors. We present an empirical study of the distinctive Boulogne-sur-Mer sh market (where both buyers and sellers can choose totrade by either bidding or bargaining), focused on the interactionsamong agents. The approach we adopt derives from the studies ofmutualistic ecosystems, where the agents are of two different types(like in plants - pollinators networks) and the interactions only takeplace between agents of different kind, bringing naturally a benefit for both. In our context, where the two kinds of agents are buyersand sellers, our study shows that their interactions, not only bringthe economic benefits for the directly involved agents, but they alsocontribute to the stability of the market. Our results help to under-stand the surprising coexistence of the two forms of markets in theBoulogne sur Mer sh-market.