| |
|
|
Economics Seminar
Institute of Mathematical Economics
and
Department of Business Administration and Economics
Vorträge im Spring 13Optimal Stopping under Private Information | Philipp Strack, Bonn University
| | Tuesday, 09.04.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. | | |
| On Dynkin games with incomplete information | Dr. Christine Grun, Bonn University
| | Tuesday, 16.04.2013 | | 4.15 - 5.45 p.m. | | in W9-139 | | No download available. | | |
| The robustness of incomplete penal codes in repeated interactions | Olivier Gossner, LSE and Paris School of Economics
| | Tuesday, 16.04.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. | | |
| Stochastic Fictitious Play with Continuous Action Sets, S.Perkins and D.S.Leslie | David Leslie, Bristol University
| | Tuesday, 23.04.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. |
Continuous action space games form a natural extension to normal form games with finite action sets. However, whilst learning dynamics in normal form games are now well studied, it is not until recently that their continuous action space counterparts have been examined. We extend stochastic fictitious play to the continuous action space framework. In normal form games the limiting behaviour of a discrete time learning process is often studied using its continuous time counterpart via stochastic approximation. In this paper we study stochastic fictitious play in games with continuous action spaces using the same method. This requires the asymptotic pseudo-trajectory approach to stochastic approximation to be extended to Banach spaces. In particular the limiting behaviour of stochastic fictitious play is studied using the associated smooth best response dynamics on the space of finite signed measures. Using this approach, stochastic fictitious play is shown to converge to an equilibrium point in single population negative definite games, two-player zero-sum games and N-player potential games, when they have Lipschitz continuous rewards. | | |
| "Routinization-Biased Technical Change and Globalization: A Theoretical Exploration of Labor Market Polarization" | Jean Mercenier, Paris II
| | Tuesday, 30.04.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. | | |
| Preference-dependent learning in the Centipede Game: a theoretical and experimental study | Astrid Gamba, Max Planck Institute of Economics
| | Tuesday, 07.05.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. |
We study the interaction of individuals with heterogeneous preference types in the strategic context of a six-stage Centipede game. We adopt a version of Self-confirming equilibrium, whereby individuals maximize their subjective expected utilities, given their preference types (e.g., selfish or altruistic) and their type-specific and possibly wrong conjectures on the opponent's strategies. Such equilibrium with off-path prediction errors has a plausible learning interpretation (i.e., fictitious play) under the assumption that individuals learn their opponent's strategies via their own observations of past interactions. We test our learning interpretation in an experiment, where we study the learning dynamics of a heterogeneous population of individuals, who are classified according to their social preferences and interact anonymously along 40 repetitions of the six-stage Centipede game. We study how the long-run type-specific conjectures and behavior change under different ex post information structures. We find that if individuals rely only on their own observations of co-players' past moves, in the long run heterogeneous behavior resembles a Self-confirming equilibrium. Off-path prediction errors turn out to be type-specific: selfish types have coarser conjectures about the opponent's behavior with respect to more altruistic types. When feedbacks on past play are more informative (aggregate frequencies of moves actually taken by individuals in the co-player’s role or aggregate frequencies of plans of actions adopted by individuals in the co-player’s role) the long run play is closer to a Bayesian Nash equilibrium with a common and correct belief about the play | | |
| The Virtues of Hesitation | Maxwell Stinchcombe, UT Austin
| | Tuesday, 14.05.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. |
In many economic, political and social situations, circumstances
change at random points in time, reacting is costly, and changes appropriate
to present circumstances may be inappropriate to later changes, requiring further
costly change. Waiting is informative if the hazard rate for the arrival of
the next change is non-constant. We identify two broad classes of situations:
in the first, delayed reaction is optimal only when the hazard rate of further
changes is decreasing; in the second, it is optimal only when the hazard rate
of further changes is increasing. The first class of situations correspond to
having waited long enough to know that future changes in circumstances are
comfortably in the future, and the associated non-optimality of action in the
face of an increasing hazard rate corresponds to the counsel of patience in
unsettled circumstances. The second class of situations corresponds to the
delay of costly precautionary steps until the danger is clear enough. These
results in non-stationary dynamic optimization provide a new set of motivations
for building delay into legislative and other decision systems, and arise
from extensions of semi-Markovian decision theory. | | |
| THE COST OF SEGREGATION IN SOCIAL NETWORKS | Nizar Allouch, Queen Mary, University of London
| | Tuesday, 21.05.2013 | | 6.15 - 7.45pm | | in W9-109 | | Paper for the talk |
This paper analyses the welfare eff ects of segregation on the private provision of public goods. While most research agrees that segregation undermines public goods provision the fi ndings are mixed for private provision: the limited social interactions across groups may either impede or increase voluntary contributions. Surprisingly, very little light is shed in the literature on the eff ect of the network structure of social interactions on private provision. This paper, fi rst, develops an index, called the Bonacich transfer index, for general network structures of social interactions, which, roughly speaking, measures the rate of crowding-out of government intervention. Then, the paper shows that when applied to network structures that display segregation, the Bonacich transfer index vanishes asymptotically, which suggests that crowding-out may be virtually complete in large segregated societies. | | |
| Almost-Rational Learning of Nash Equilibrium without Absolute Continuity | Tom Norman, Magdalen College, University of Oxford
| | Tuesday, 28.05.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | Paper for the talk |
If players learn to play an infinitely repeated game using Bayesian learning, it is known that their strategies eventually approximate Nash equilibria of the repeated game under an absolute-continuity assumption on their prior beliefs. I suppose here that Bayesian learners do not start with such a ``grain of truth'', but when their finitely complex beliefs struggle to explain observed play, they undergo a random ``paradigm shift'' in those beliefs. I show that, if the players choose smooth approximately optimal responses, such a process spends all but a small fraction of the time approximating a Nash equilibrium of the repeated game, irrespective of the players' prior beliefs. | | |
| The regional implications of financial market development: Credit rationing, trade, and location | Tobias Seidel, Universitaet Duisburg-Essen
| | Tuesday, 04.06.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. | | |
| tba | Nicolas de Roos, University of Sydney
| | Tuesday, 11.06.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. | | |
| "Labour Market Frictions, Monetary Policy and Durable Goods" | Jun.-Prof. Dr. Matthias Hertweck, Universität Konstanz
| | Tuesday, 18.06.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | http://ideas.repec.org/p/knz/dpteco/1209.html | | |
| Zero-sum repeated games: counterexamples to the existence of the asymptotic value and the conjecture maxmin=lim vn | Bruno Ziliotto , Université Toulouse 1
| | Tuesday, 25.06.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | Paper for the talk |
We provide an example of a two-player zero-sum repeated game with public signals and perfect
observation of the actions, where neither the value of the lambda-discounted game nor the value
of the n-stage game converges, when respectively lambda goes to 0 and n goes to in finity. It is
a counterexample to two long-standing conjectures, formulated by Mertens : Fi rst, in any zero-
sum repeated game, the asymptotic value exists, and secondly, when Player 1 is more informed
than Player 2, Player 1 is able to guarantee the limit value of the n-stage game in the long run.
The aforementioned example involves seven states, two actions and two signals for each player.
Remarkably, players observe the payoff s, and play in turn (at each step the action of one player
only has an eff ect on the payoff and the transition). Moreover, it can be adapted to fit in the class
of standard stochastic games where the state is not observed. | | |
| tba | Jörg Oechssler, Heidelberg University
| | Tuesday, 02.07.2013 | | 6.15 - 7.45 p.m. | | in W9-109 | | No download available. | | |
| TBA | Prof. Peter Howitt, Brown University
| | Tuesday, 24.09.2013 | | 6.15 - 7.45pm | | in W9-109 | | No download available. | | |
|
|
