Evolutionary Stability of First Price Auctions

This paper studies the evolutionary stability of the unique Nash equilibrium of a first price sealed bid auction. It is shown that the Nash equilibrium is not asymptotically stable under payoff monotonic dynamics for arbitrary initial popu- lations. In contrast, when the initial population includes a continuum of strategies around the equilibrium, the replicator dynamic does converge to the Nash equilibrium. Simulations are presented for the replicator and Brown-von Neumann-Nash dynamics. They suggest that the convergence for the replicator dynamic is slow compared to the Brown-von Neumann-Nash dynamics.

Price Formation by Bargaining and Posted Prices

We study markets with two types of agents. Sellers have an indivisible good for sale, and their reservation value is zero. Buyers are randomly matched with sellers, and they value the good at unity. Sellers may be matched with any positive number of buyers, and they may choose to determine the price of the good either by bargaining or by posting prices. These choices are relevant only when a seller meets exactly one buyer. If two or more buyers are matched to a seller the buyers engage in an auction. The agents may choose whether to go to markets with bargaining or posted prices. We show that both market structures are equilibria but that they do not co-exist. Markets with posted prices are shown to be the unique evolutionary stable equilibrium.Bargaining;posted prices;random matching.

Equivalence of Auctions and Posted Prices

We determine the equilibrium in two transaction mechanisms: auctions and posted prices. Agents choose whether to participate in markets where trades are consummated by auctions or in markets where sellers post prices. We show that the selling mechanisms are practically equivalent. Previous studies have shown that auction markets emerge as a unique evolutionary stable equilibrium when compared to bargaining markets. Posted price market dominate bargaining markets similarly.Auctions;posted prices;random matching.

Local and Global Interactions in an Evolutionary Resource Game

Conditions for the emergence of cooperation in a spatial common-pool resource game are studied. This combines in a unique way local and global interactions. A fixed number of harvesters are located on a spatial grid. Harvesters choose among three strategies: defection, cooperation, and enforcement. Individual payoffs are affected by both global factors, namely, aggregate harvest and resource stock level, and local factors, such as the imposition of sanctions on neighbors by enforcers. The evolution of strategies in the population is driven by social learning through imitation. Numerous types of equilibria exist in these settings. An important new finding is that clusters of cooperators and enforcers can survive among large groups of defectors. We discuss how the results contrast with the non-spatial, but otherwise similar, game of Sethi and Somanathan (1996).Common property, Cooperation, Evolutionary game theory, Global interactions, Local interactions, Social norms

Spatial Evolution of Social Norms in a Common-Pool Resource Game

We study the conditions for the emergence of cooperation in a spatial common-pool resource game. We consider three types of agents: cooperators, defectors and enforcers. The role of enforcers is to punish defectors for overharvesting the resource. Agents are located around a circle and they only observe the actions of their two nearest neighbors. Their payoffs are determined by both local and global interactions and they modify their actions by imitating the strategy in their neighborhood with the highest payoffs on average. Using theoretical and numerical analysis, we find that a large diversity of equilibria exists in this game. In particular, we derive conditions for the occurrence of equilibria in which the three strategies coexist. We also discuss the stability of these equilibria. Finally, we show that introducing resource dynamics favors the occurrence of cooperative equilibria.Common property, Evolutionary game theory, Local interactions game, Self-organization, Cooperation

Evolution of optimal L\'evy-flight strategies in human mental searches

Recent analysis of empirical data [F. Radicchi, A. Baronchelli & L.A.N. Amaral. PloS ONE 7, e029910 (2012)] showed that humans adopt L\'evy flight strategies when exploring the bid space in on-line auctions. A game theoretical model proved that the observed L\'evy exponents are nearly optimal, being close to the exponent value that guarantees the maximal economical return to players. Here, we rationalize these findings by adopting an evolutionary perspective. We show that a simple evolutionary process is able to account for the empirical measurements with the only assumption that the reproductive fitness of a player is proportional to her search ability. Contrarily to previous modeling, our approach describes the emergence of the observed exponent without resorting to any strong assumptions on the initial searching strategies. Our results generalize earlier research, and open novel questions in cognitive, behavioral and evolutionary sciences.Comment: 8 pages, 4 figure

Environmental analysis for application layer networks

Die zunehmende Vernetzung von Rechnern über das Internet lies die Vision von Application Layer Netzwerken aufkommen. Sie umfassen Overlay Netzwerke wie beispielsweise Peer-to-Peer Netzwerke und Grid Infrastrukturen unter Verwendung des TCP/IP Protokolls. Ihre gemeinsame Eigenschaft ist die redundante, verteilte Bereitstellung und der Zugang zu Daten-, Rechen- und Anwendungsdiensten, während sie die Heterogenität der Infrastruktur vor dem Nutzer verbergen. In dieser Arbeit werden die Anforderungen, die diese Netzwerke an ökonomische Allokationsmechanismen stellen, untersucht. Die Analyse erfolgt anhand eines Marktanalyseprozesses für einen zentralen Auktionsmechanismus und einen katallaktischen Markt. --Grid Computing

Participation in and Compliance with Public Voluntary Environmental Programs: An Evolutionary Approach

The joint evolution of participating and complying firms in a public VA, along with the evolution of the pollution stock is examined. Replicator dynamics modeling participation and compliance are combined with pollution stock dynamics. Fast-slow selection dynamics are used to capture the fact that decisions to participate in and further comply with the public VA evolve in different time scales. Evolutionary stable (ES) equilibria depend on the structure of the legislation and auditing probability. Partial participation and partial compliance can be ES equilibria, with possible multiplicities, in addition to the monomorphic equilibria of full (non) compliance. Convergence to these equilibria could be monotonic or oscillating. Full participation and compliance can be attained if the regulator is pre-committed to certain legislation and inspection probabilities, or by appropriate choices of the legislatively set emission level and the non-compliance fine.Voluntary agreements, Participation, Compliance, Evolutionary stability, Replicator dynamics

Economic Instruments and Induced Innovation: The Case of End-of-Life Vehicles European Policies

The paper addresses the dynamic-incentive effect of environmental policy instruments when innovation is uncertain and occurs in very complex industrial subsystems. The case of end-of-life vehicles (ELVs) is considered focusing predominantly on the effects of the European Directive adopted in 2000 which stipulated economic instruments as free take-back, and on the voluntary agreements in place in many EU countries. The ELV case study is an example of a framework where policy-making faces an intrinsic dynamic and systemic environment. Coherent sequences of single innovations taking place in both upstream (car making) and downstream (car recycling/recovery) of the ELV system can give rise to different “innovation paths”, in accordance with cost-benefit considerations, technological options and capabilities associated to the different industrial actors involved. The impact of economic instruments on innovation paths, in particular free take-back, is considered. Deficiencies or difficulties concerning the transmission of incentives between different industries can prevent the creation of new recycling/recovery/reuse markets, giving rise to other less preferable and unexpected outcomes. The implication for policy is a need for an integrated policy approach, as enforceable VAs, in order to create a shared interindustry interest for innovation and to reduce the possible adverse effects which economic instruments exert on innovation through cost benefit impacts on key industrial and waste-related agents involved in the ELV management system. These advantages should be taken into account vis à vis the emergence of Integrated Product Policy (IPP) as a leading concept of EU environmental policy and the associated shift from "extended producer responsibility" to "extended product responsibility".ELV, Induced innovation, Dynamic efficiency, Economic instruments, Recycling

An Open Source Based Data Warehouse Architecture to Support Decision Making in the Tourism Sector

In this paper an alternative Tourism oriented Data Warehousing architecture is proposed which makes use of the most recent free and open source technologies like Java, Postgresql and XML. Such architecture's aim will be to support the decision making process and giving an integrated view of the whole Tourism reality in an established context (local, regional, national, etc.) without requesting big investments for getting the necessary software.Tourism, Data warehousing architecture