Matthew Olckers

Thematic seminars
Economic theory seminar

Matthew Olckers

École d'économie de Paris, PSE
Friend-based ranking

IBD Salle 16

Îlot Bernard du Bois - Salle 16

5-9 boulevard Maurice Bourdet
13001 Marseille

Thursday, December 13 2018| 12:00pm to 1:15pm

Mathieu Faure: mathieu.faure[at]
Gaëtan Fournier: gaetan.fournier[at]


We analyze the design of a mechanism to extract ordinal information dis-seminated in a social network. We show that friend-based ranking—the report by agents on the characteristics of their neighbors—is a necessary condition for ex post incentive-compatible and efficient mechanism design. We characterize the windmill network as the sparsest social network for which the planner can construct a complete ranking. When complete rankings cannot be achieved, expost incentive-compatible and efficient mechanisms arise when social networks are bipartite or composed of triangles. We illustrate these findings using real social networks in India and Indonesia.

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