In Townsend's matching model, there is an infinity of traders indexed by i j where i = I or 2 and j is an integer which may be positive or negative. At period t , trader l j is matched with trader 2 , j + t. In particular, no two traders ever meet twice and no trader's behavior can directly or indirectly influence the behavior of his future trading partners. In the absence of institutions, players possess no information about their current partner's past behavior.

PAUL R. MILGRO, PAUL R. MILGRO - THE ROLE O…, loc. 70