1,499 research outputs found
The demise of constant price impact functions and single-time step models of speculation
Constant and symmetric price impact functions, most commonly used in
agent-based market modelling, are shown to give rise to paradoxical and
inconsistent outcomes in the simplest case of arbitrage exploitation when
open-hold-close actions are considered. The solution of the paradox lies in the
non-constant nature of real-life price impact functions. A simple model that
includes explicit position opening, holding, and closing is briefly introduced
and its information ecology discussed, shedding new light on the relevance of
the Minority Game to the study of financial markets.Comment: 10 pages, 2 figures. Proceedings of APFA5 conferenc
The Local Minority Game
Ecologists and economists try to explain collective behavior in terms of
competitive systems of selfish individuals with the ability to learn from the
past. Statistical physicists have been investigating models which might
contribute to the understanding of the underlying mechanisms of these systems.
During the last three years one intuitive model, commonly referred to as the
Minority Game, has attracted broad attention. Powerful yet simple, the minority
game has produced encouraging results which can explain the temporal behaviour
of competitive systems. Here we switch the interest to phenomena due to a
distribution of the individuals in space. For analyzing these effects we modify
the Minority Game and the Local Minority Game is introduced. We study the
system both numerically and analytically, using the customary techniques
already developped for the ordinary Minority Game
Harms and benefits from social imitation
We study the role of imitation within a model of economics with adaptive
agents. The basic ingredients are those of the Minority Game. We add the
possibility of local information exchange and imitation of the neighbour's
strategy. Imitators should pay a fee to the imitated. Connected groups are
formed, which act as if they were single players. Coherent spatial areas of
rich and poor agents result, leading to the decrease of local social tensions.
Size and stability of these areas depends on the parameters of the model.
Global performance measured by the attendance volatility is optimised at
certain value of the imitation probability. The social tensions are suppressed
for large imitation probability, but due to the price paid by the imitators the
requirements of high global effectivity and low social tensions are in
conflict, as well as the requirements of low global and low local wealth
differences.Comment: 11 pages, elsart style, to appear in the proceedings of NATO ARW on
Application of Physics in Economic Modelling, Prague, 8-10 February 200
Self-organization, resources and strategies in a minority game
We find that the existence of self-organization of the members of a recently
proposed minority game, depends on the type of update rules used. The resulting
resource distribution is studied in some detail, and a related strategy scheme
is considered, as a tool to improve the understanding of the modelComment: 4 pages (barely), 3 figure
The Minority Game with interactions
We partially modify the rules of the Minority Game (MG) by introducing some
degree of local information in the game, which is only available for some
agents, called the interacting agents. Our work shows that, for small values of
the new parameter of the model (the fraction of interacting agents), there is
an improvement of the use of the resources with respect to the MG, while as
this number grows the response of the system changes, and ends up behaving
worst than the usual MG.Comment: 9 pages, 4 figures; typoos corrected; references upadted; Physica A
-like LaTe
Dynamics of the Time Horizon Minority Game
We present exact analytic results for a new version of the Minority Game (MG)
in which strategy performance is recorded over a finite time horizon. The
dynamics of this Time Horizon Minority Game (THMG) exhibit many distinct
features from the MG and depend strongly on whether the participants are fed
real, or random, history strings. The THMG equations are equivalent to a Markov
Chain, and yield exact analytic results for the volatility given a specific
realization for the quenched strategy disorder.Comment: Latex file, 11 pages, 6 figure
The Full Strategy Minority Game
The Full Strategy Minority Game (FSMG) is an instance of the Minority Game
(MG) which includes a single copy of every potential agent. In this work, we
explicitly solve the FSMG thanks to certain symmetries of this game.
Furthermore, by considering the MG as a statistical sample of the FSMG, we
compute approximated values of the key variable {\sigma}2/N in the symmetric
phase for different versions of the MG. As another application we prove that
our results can be easily modified in order to handle certain kind of initial
biased strategies scores, in particular when the bias is introduced at the
agents' level. We also show that the FSMG verifies a strict period two dynamics
(i.e., period two dynamics satisfied with probability 1) giving, to the best of
our knowledge, the first example of an instance of the MG for which this
feature can be analytically proved. Thanks to this property, it is possible to
compute in a simple way the probability that a general instance of the MG
breaks the period two dynamics for the first time in a given simulation.Comment: To appear in Physica
Evolutionary minority game with heterogeneous strategy distribution
We present detailed numerical results for a modified form of the so-called
Minority Game, which provides a simplified model of a competitive market. Each
agent has a limited set of strategies, and competes to be in a minority. An
evolutionary rule for strategy modification is included to mimic simple
learning. The results can be understood by considering crowd formation within
the population.Comment: Revtex file + 4 figure
Crowd-anticrowd theory of the Minority Game
The Minority Game is a simple yet highly non-trivial agent-based model for a
complex adaptive system. Despite its importance, a quantitative explanation of
the game's fluctuations which applies over the entire parameter range of
interest has so far been lacking. We provide such a quantitative description
based on the interplay between crowds of like-minded agents and their
anti-correlated partners (anticrowds).Comment: Shortened version of cond-mat/0003486. Submitted for publicatio
Evolutionary freezing in a competitive population
We show that evolution in a population of adaptive agents, repeatedly
competing for a limited resource, can come to an abrupt halt. This transition
from evolutionary to non-evolutionary behavior arises as the global resource
level is changed, and is reminiscent of a phase transition to a frozen state.
Its origin lies in the inductive decision-making of the agents, the limited
global information that they possess and the dynamical feedback inherent in the
system.Comment: LaTeX file + 4 separate (pdf) figures. Revised version has minor
change in Fig. 3 axis labe
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