A Response to the Critics

My article on refugee burden-sharing ( Refugee Burden-Sharing: A Modest Proposal, 22 YALE J. INT\u27L. L. 243 (1997)) advances a novel approach to an appalling problem that desperately needs all the fresh thinking it can get. Unfortunately, the critique by Deborah Anker, Joan Fitzpatrick, and Andrew Shacknove, Crisis and Cure: A Reply to Hathaway/Neve and Schuck, 11 HARv. HUM. RTS. J. 295 (1998), while both serious and respectful, misrepresents my proposal in a number of significant respects-misrepresentations that I pointed out to them when they sent me a draft of their critique only days before this draft was to go to the printer. I shall briefly address each of those misrepresentations in the order in which they appear in their critique

Time Scales in Evolutionary Dynamics

Evolutionary game theory has traditionally assumed that all individuals in a population interact with each other between reproduction events. We show that eliminating this restriction by explicitly considering the time scales of interaction and selection leads to dramatic changes in the outcome of evolution. Examples include the selection of the inefficient strategy in the Harmony and Stag-Hunt games, and the disappearance of the coexistence state in the Snowdrift game. Our results hold for any population size and in the presence of a background of fitness.Comment: Final version with minor changes, accepted for publication in Physical Review Letter

Chaos and unpredictability in evolutionary dynamics in discrete time

A discrete-time version of the replicator equation for two-strategy games is studied. The stationary properties differ from that of continuous time for sufficiently large values of the parameters, where periodic and chaotic behavior replace the usual fixed-point population solutions. We observe the familiar period-doubling and chaotic-band-splitting attractor cascades of unimodal maps but in some cases more elaborate variations appear due to bimodality. Also unphysical stationary solutions have unusual physical implications, such as uncertainty of final population caused by sensitivity to initial conditions and fractality of attractor preimage manifolds.Comment: 4 pages, 4 figure

Imperfect Imitation Can Enhance Cooperation

The promotion of cooperation on spatial lattices is an important issue in evolutionary game theory. This effect clearly depends on the update rule: it diminishes with stochastic imitative rules whereas it increases with unconditional imitation. To study the transition between both regimes, we propose a new evolutionary rule, which stochastically combines unconditional imitation with another imitative rule. We find that, surprinsingly, in many social dilemmas this rule yields higher cooperative levels than any of the two original ones. This nontrivial effect occurs because the basic rules induce a separation of timescales in the microscopic processes at cluster interfaces. The result is robust in the space of 2x2 symmetric games, on regular lattices and on scale-free networks.Comment: 4 pages, 4 figure

Global Legal Pluralism

Some challenges of legal globalization closely resemble those formulated earlier for legal pluralism: the irreducible plurality of legal orders, the coexistence of domestic state law with other legal orders, the absence of a hierarchically superior position transcending the differences. This review discusses how legal pluralism engages with legal globalization and how legal globalization utilizes legal pluralism. It demonstrates how several international legal disciplines---comparative law, conflict of laws, public international law, and European Union law---have slowly begun to adopt some ideas of legal pluralism. It shows how traditional themes and questions of legal pluralism---the definition of law, the role of the state, of community, and of space---are altered under conditions of globalization. It addresses interrelations between different legal orders and various ways, both theoretical and practical, to deal with them. And it provides an outlook on the future of global legal pluralism as theory and practice of global law

Global Legal Pluralism

Some challenges of legal globalization closely resemble those formulated earlier for legal pluralism: the irreducible plurality of legal orders, the coexistence of domestic state law with other legal orders, the absence of a hierarchically superior position transcending the differences. This review discusses how legal pluralism engages with legal globalization and how legal globalization utilizes legal pluralism. It demonstrates how several international legal disciplines---comparative law, conflict of laws, public international law, and European Union law---have slowly begun to adopt some ideas of legal pluralism. It shows how traditional themes and questions of legal pluralism---the definition of law, the role of the state, of community, and of space---are altered under conditions of globalization. It addresses interrelations between different legal orders and various ways, both theoretical and practical, to deal with them. And it provides an outlook on the future of global legal pluralism as theory and practice of global law

Exploring the WFO Option for Global Banking Regulation

The Global Financial Crisis and the global operations by participants in the financial services industry has led observers and even senior public representatives to call for global regulatory solutions that go beyond the current, transnational regulatory network (TRN) framework provided by the G20, the Financial Stability Board and the Basel Committee on Banking Supervision. The concept of a global banking regulator has often been advocated, but this is not remotely politically viable. Recently the imaginative concept of a World Financial Organization (WFO), that would follow the model of the World Trade Organization (WTO), has been proposed. Although attractive in that such a framework might seem to offer a less dramatic inroad on national sovereignty than might a global regulator, the WFO idea has difficulties as well. In particular, financial and especially banking regulation is quite unlike trade regulation. Trade regulation focuses on access to markets and fairness among nations. Banking regulation is concerned with safe and sound operations of specific financial institutions and with the threats to financial stability that such operations might pose. This latter kind of regulation demands highly specific and very responsive regulatory action that does not fit well with the cumbersome processes of international trade regulation. This paper argues that the real problems begin with the globalized nature of specific modern banking operations and that these problems should first be addressed domestically, not internationally. At the same time, international coordination (as opposed to governance) is always critically important. While the TRNs can be criticized for mistakes of their own, their activities provide much more immediate and practical focus than would an abstract WFO treaty that might attempt to move beyond the access to financial markets already addressed in the Annex on Financial Services of the General Agreement on Trade in Services and analogous regional agreements, such as the North American Free Trade Agreement , ch. 14. The paper therefore argues that the WFO proposal is conceptually misaligned to the problems that must be addressed, and that it is also impractical as a short or medium term solution to the problems of financial instability

Citizen Social Lab: A digital platform for human behaviour experimentation within a citizen science framework

Cooperation is one of the behavioral traits that define human beings, however we are still trying to understand why humans cooperate. Behavioral experiments have been largely conducted to shed light into the mechanisms behind cooperation and other behavioral traits. However, most of these experiments have been conducted in laboratories with highly controlled experimental protocols but with varied limitations which limits the reproducibility and the generalization of the results obtained. In an attempt to overcome these limitations, some experimental approaches have moved human behavior experimentation from laboratories to public spaces, where behaviors occur naturally, and have opened the participation to the general public within the citizen science framework. Given the open nature of these environments, it is critical to establish the appropriate protocols to maintain the same data quality that one can obtain in the laboratories. Here, we introduce Citizen Social Lab, a software platform designed to be used in the wild using citizen science practices. The platform allows researchers to collect data in a more realistic context while maintaining the scientific rigour, and it is structured in a modular and scalable way so it can also be easily adapted for online or brick-and-mortar experimental laboratories. Following citizen science guidelines, the platform is designed to motivate a more general population into participation, but also to promote engaging and learning of the scientific research process. We also review the main results of the experiments performed using the platform up to now, and the set of games that each experiment includes. Finally, we evaluate some properties of the platform, such as the heterogeneity of the samples of the experiments and their satisfaction level, and the parameters that demonstrate the robustness of the platform and the quality of the data collected.Comment: 17 pages, 11 figures and 4 table

The Shared Reward Dilemma

One of the most direct human mechanisms of promoting cooperation is rewarding it. We study the effect of sharing a reward among cooperators in the most stringent form of social dilemma, namely the Prisoner's Dilemma. Specifically, for a group of players that collect payoffs by playing a pairwise Prisoner's Dilemma game with their partners, we consider an external entity that distributes a fixed reward equally among all cooperators. Thus, individuals confront a new dilemma: on the one hand, they may be inclined to choose the shared reward despite the possibility of being exploited by defectors; on the other hand, if too many players do that, cooperators will obtain a poor reward and defectors will outperform them. By appropriately tuning the amount to be shared a vast variety of scenarios arises, including traditional ones in the study of cooperation as well as more complex situations where unexpected behavior can occur. We provide a complete classification of the equilibria of the $n$-player game as well as of its evolutionary dynamics.Comment: Major rewriting, new appendix, new figure