Wyniki wyszukiwania - Biblioteka Nauki

1

Collusion and seasonality of market price - A case of fixed market shares

100%

Bejger S.

Business and Economic Horizons

|

2010

|

tom 2

|

nr 2

48-59

EN

The paper develops a simple supergame model of collusion that focuses on the role of fixed (exogenous to game played) system of quantity market shares. Conclusions implied by the model could be used to motivate data - saving markers of collusion based on market price behavior. Following conclusions of the theoretical model we propose marker of collusion based on detecting changes in seasonal parameters of prices in periods of possible collusion. An empirical application of method has been done on well known data of Lysine cartel case.

2

The role of dynamics for trust development. An experimental study

100%

Zawojska E.

Ekonomia. Rynek, Gospodarka, Społeczeństwo

|

2014

|

nr 38

129-149

EN

We report results from a trust game applied in a dynamic setting, which enhances investment possibilities and offers higher potential payoff from cooperation. The proposed approach better reflects the predicaments people face in concluding informal contracts and enables to investigate dynamics of cooperation relationships between players. Although, transferred shares of the disposable endowment do not differ significantly across the standard and modified games, in the absolute values people send more in the dynamic context. Our results suggest that the dynamic setting of the relationship, which has been often ignored in previous studies, might be an important determinant of trust.

3

Convergence method, properties and computational complexity for Lyapunov games

88%

Clempner J. , Poznyak A.

|

tom 21

|

nr 2

349-361

EN

We introduce the concept of a Lyapunov game as a subclass of strictly dominated games and potential games. The advantage of this approach is that every ergodic system (repeated game) can be represented by a Lyapunov-like function. A direct acyclic graph is associated with a game. The graph structure represents the dependencies existing between the strategy profiles. By definition, a Lyapunov-like function monotonically decreases and converges to a single Lyapunov equilibrium point identified by the sink of the game graph. It is important to note that in previous works this convergence has not been guaranteed even if the Nash equilibrium point exists. The best reply dynamics result in a natural implementation of the behavior of a Lyapunov-like function. Therefore, a Lyapunov game has also the benefit that it is common knowledge of the players that only best replies are chosen. By the natural evolution of a Lyapunov-like function, no matter what, a strategy played once is not played again. As a construction example, we show that, for repeated games with bounded nonnegative cost functions within the class of differentiable vector functions whose derivatives satisfy the Lipschitz condition, a complex vector-function can be built, where each component is a function of the corresponding cost value and satisfies the condition of the Lyapunov-like function. The resulting vector Lyapunov-like function is a monotonic function which can only decrease over time. Then, a repeated game can be represented by a one-shot game. The functionality of the suggested method is successfully demonstrated by a simulated experiment.

4

Convergence method, properties and computational complexity for Lyapunov games

63%

Clempner J. B. , Poznyak A. S.

International Journal of Applied Mathematics and Computer Science

|

2011

|

tom Vol. 21, no 2

349-361

EN

We introduce the concept of a Lyapunov game as a subclass of strictly dominated games and potential games. The advantage of this approach is that every ergodic system (repeated game) can be represented by a Lyapunov-like function. A direct acyclic graph is associated with a game. The graph structure represents the dependencies existing between the strategy profiles. By definition, a Lyapunov-like function monotonically decreases and converges to a single Lyapunov equilibrium point identified by the sink of the game graph. It is important to note that in previous works this convergence has not been guaranteed even if the Nash equilibrium point exists. The best reply dynamics result in a natural implementation of the behavior of a Lyapunov-like function. Therefore, a Lyapunov game has also the benefit that it is common knowledge of the players that only best replies are chosen. By the natural evolution of a Lyapunov-like function, no matter what, a strategy played once is not played again. As a construction example, we show that, for repeated games with bounded nonnegative cost functions within the class of differentiable vector functions whose derivatives satisfy the Lipschitz condition, a complex vector-function can be built, where each component is a function of the corresponding cost value and satisfies the condition of the Lyapunov-like function. The resulting vector Lyapunov-like function is a monotonic function which can only decrease over time. Then, a repeated game can be represented by a one-shot game. The functionality of the suggested method is successfully demonstrated by a simulated experiment.