scholarly journals Pairwise imitation and evolution of the social contract

2020 ◽  
Author(s):  
Nicola Campigotto
Keyword(s):  
Social Contract ◽  
Decision Rules ◽  
Interaction Process ◽  
Assortative Matching ◽  
Response Learning ◽  
Stag Hunt ◽  
Long Run ◽  
Best Response ◽  
The Social

AbstractThis paper studies the evolution of conventions in Stag Hunt games when agents’ behaviour depends on pairwise payoff comparisons. The results of two imitative decision rules are compared with each other and with those obtained when agents myopically best respond to the distribution of play. These rules differ in terms of their rationale, their requirements, and the extent to which they make individuals learn from others. Depending on payoffs and the interaction process being considered, best response learning can cause either the rewarding All Stag equilibrium or the inefficient All Hare equilibrium to emerge as the long-run convention. In contrast, pairwise imitation favours the emergence of the Pareto-inferior equilibrium. This result is robust to assuming assortative matching and some heterogeneity in decision rules.

scholarly journals BEST-RESPONSE DYNAMICS IN A BIRTH-DEATH MODEL OF EVOLUTION IN GAMES

2010 ◽  
Vol 12 (02) ◽  
pp. 197-204 ◽  
Author(s):  
CARLOS ALÓS-FERRER ◽  
ILJA NEUSTADT
Keyword(s):  
Mutation Rate ◽  
Decision Rules ◽  
Direct Proof ◽  
Mutation Rates ◽  
Death Process ◽  
Explicit Computation ◽  
Response Dynamics ◽  
Long Run ◽  
Best Response ◽  
Birth Death

We consider a model of evolution with mutations as in Kandori et al. (1993) [Kandori, M., Mailath, G.J., Rob, R., 1993. Learning, mutation, and long run equilibria in games. Econometrica 61, 29–56], where agents follow best-response decision rules as in Sandholm (1998) [Sandholm, W., 1998. Simple and clever decision rules for a model of evolution. Economics Letters 61, 165–170]. Contrary to those papers, our model gives rise to a birth-death process, which allows explicit computation of the long-run probabilities of equilibria for given values of the mutation rate and the population size. We use this fact to provide a direct proof of the stochastic stability of risk-dominant equilibria as the mutation rate tends to zero, and illustrate the outcomes of the dynamics for positive mutation rates.

D?r al-?arb as the Motherland? The Muslim Tatars of (the Grand Duchy of) Lithuania and Social Contract

2017 ◽  
Vol 10 (2) ◽  
pp. 157-177
Author(s):  
Egdūnas Račius
Keyword(s):  
Twentieth Century ◽  
Social Contract ◽  
Social Consequences ◽  
Nation State ◽  
The Social ◽  
State And Society ◽  
Muslim Minority ◽  
Grand Duchy Of Lithuania ◽  
In The Beginning ◽  
Grand Duchy

Muslim presence in Lithuania, though already addressed from many angles, has not hitherto been approached from either the perspective of the social contract theories or of the compliance with Muslim jurisprudence. The author argues that through choice of non-Muslim Grand Duchy of Lithuania as their adopted Motherland, Muslim Tatars effectively entered into a unique (yet, from the point of Hanafi fiqh, arguably Islamically valid) social contract with the non-Muslim state and society. The article follows the development of this social contract since its inception in the fourteenth century all the way into the nation-state of Lithuania that emerged in the beginning of the twentieth century and continues until the present. The epitome of the social contract under investigation is the official granting in 1995 to Muslim Tatars of a status of one of the nine traditional faiths in Lithuania with all the ensuing political, legal and social consequences for both the Muslim minority and the state.

The Evolutionary Dynamics of Decision Rule Selection

2017 ◽  
Author(s):  
Michael Laver ◽  
Ernest Sergenti
Keyword(s):  
Decision Rule ◽  
Positive Feedback ◽  
Party System ◽  
Evolutionary Dynamics ◽  
Decision Rules ◽  
Past Performance ◽  
Party Leaders ◽  
Track Record ◽  
Long Run ◽  
Survival Of The Fittest

This chapter extends the survival-of-the-fittest evolutionary environment to consider the possibility that new political parties, when they first come into existence, do not pick decision rules at random but instead choose rules that have a track record of past success. This is done by adding replicator-mutator dynamics to the model, according to which the probability that each rule is selected by a new party is an evolving but noisy function of that rule's past performance. Estimating characteristic outputs when this type of positive feedback enters the dynamic model creates new methodological challenges. The simulation results show that it is very rare for one decision rule to drive out all others over the long run. While the diversity of decision rules used by party leaders is drastically reduced with such positive feedback in the party system, and while some particular decision rule is typically prominent over a certain period of time, party systems in which party leaders use different decision rules are sustained over substantial periods.

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