00883nam a22001097a 4500008004100000100004100041245002500082260004700107300003200154520054000186773004700726221226b           ||||| |||| 00| 0 eng d  aBloch, Francis and Olckers, Matthew   aFriend-based ranking  aAmerican Economic Journal: Microeconomics   a14(2), May, 2022: p.176-214  aWe analyze the design of a mechanism to extract a ranking of individuals according to a unidimensional characteristic, such as ability or need. Individuals, connected on a social network, only have local information about the ranking. We show that a planner can construct an ex post incentive compatible and efficient mechanism if and only if every pair of friends has a friend in common. We characterize the windmill network as the sparsest social network for which the planner can always construct a complete ranking. – Reproduced   aAmerican Economic Journal: Microeconomics