Essays on equilibrium selection

The first two chapters of this thesis explore how coordination happens in simple games. The first chapter models the adaptive play of a 2 x 2 game by pairs of agents matched together from a large population. In contrast with the existing literature, I assume that agents have some control over who they are matched with - specifically, I give them the option to sometimes continue playing against the same opponent. This renewal option allows agents playing efficiently to isolate themselves from those who are not. Perhaps counterintuitively, efficient play may be less likely to survive in the long run when agents have this additional instrument, even in games with common interests. This is because isolation has two effects: it raises the returns to an efficient but fragile strategy, but it also "ghettoizes" agents playing inefficiently - they rarely learn about the efficient strategy and when they do learn about it, they rarely hear good news. I look at an extension in which agents have long memories about the performance of a strategy. With long memories, good news about an efficient strategy will be more likely to trickle down to ghettoized agents, mitigating the bias in learning. With this bias removed, long run survival of efficient play becomes more likely - even when it is not a static Nash equilibrium. Essentially, agents learn to use the renewal option to punish non-cooperators. However, the speed of learning may still be quite slow, so that ghettoization persists for a long time.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Economics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2001

Author dc:creator

• Larson, Nathan (Nathan Christopher), 1974-

Advisor dc:contributor.advisor

• Abhijit Banerjee and Glenn Ellison.

• Economics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/8651

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/8651