Recently advocates of the propensity interpretation of fitness have turned critics. To accommodate examples from the population genetics literature they conclude that fitness is better defined broadly as a family of propensities rather than the propensity to contribute descendants to some future generation. We argue that the propensity theorists have misunderstood the deeper ramifications of the examples they cite. These examples demonstrate why there are factors outside of propensities that determine fitness. We go on to argue for the more general (...) thesis that no account of fitness can satisfy the desiderata that have motivated the propensity account. (shrink)

Writers on collective action are in broad agreement that in order for a group of agents to form a collective intention, the members of that group must have beliefs about the beliefs of the other members. But in spite of the fact that this so-called "interactive knowledge" is central to virtually every account of collective intention, writers on this subject have not offered a detailed account of the nature of interactive knowledge. In this paper, we argue that such an account (...) is necessary for any adequate analysis of collective intention. Furthermore, we argue that an application of Robert Aumann's theory of interactive knowledge may be used to address several puzzling features of collective intention. CiteULike Connotea Del.icio.us What's this? (shrink)

Brian Skyrms has argued that the evolution of the social contract may be explained using the tools of evolutionary game theory. I show in the first half of this paper that the evolutionary game-theoretic models are often highly sensitive to the specific processes that they are intended to simulate. This sensitivity represents an important robustness failure that complicates Skyrms's project. But I go on to make the positive proposal that we may none the less obtain robust results by simulating the (...) population structures that existed among our evolutionary ancestors. It is by extending the evolutionary models in this way that we should pursue the project of explaining the evolution of the social contract. (shrink)

In this paper, we offer an analysis of ‘group intentions.’ On our proposal, group intentions should be understood as a state of equilibrium among the beliefs of the members of a group. Although the discussion in this paper is non-technical, the equilibrium concept is drawn from the formal theory of interactive epistemology due to Robert Aumann. The goal of this paper is to provide an analysis of group intentions that is informed by important work in economics and formal epistemology.

Human beings are highly irrational, at least if we hold to an economic standard of ‘rationality’. Experimental economics studies the irrational behavior of human beings, with the aim of understanding exactly how our behavior deviates from the Homo economicus, as ‘rational man’ has been called. Insofar as philosophical theories depend upon rationality assumptions, experimental economics is the source of both problems and (at least potential) solutions to several philosophical issues. This article offers a programmatic and highly biased survey of some (...) of these issues, with the hope of convincing the reader that experimental economics is well-deserving of careful study by philosophers. (shrink)

Common knowledge is usually defined as a state in which everyone knows that p, everyone knows that everyone knows that p, and so on, ad infinitum. This definition is usually attributed to David Lewis, despite the fact that his own formulation bears no resemblance to common knowledge as it is usually understood. In this paper, I argue that this concept of common knowledge requires revision. Contrary to usual practice, it turns out to be difficult to model formally because existing models (...) fail to distinguish between full-blown common knowledge and merely finite levels of interactive knowledge. Conceptually, the concept is incompatible with Lewis's intended purpose and obscures the explanatory role played by rational choice models. I propose that the concept of common knowledge be brought better into alignment with Lewis's actual formulation. This reconceptualization of common knowledge suggests a greater focus on explanations that make recourse to the cognitive constraints of real-world agents. (shrink)

We argue that conceptual analyses of collective action should be informed by game-theoretic analyses of collective action. In particular, we argue that Ariel Rubenstein’s so-called ‘Electronic Mail Game’ provides a useful model of collective action, and of the formation of collective intentions.

Shortest possible axiomatizations for the implicational fragments of the modal logics S4 and S5 are reported. Among these axiomatizations is included a shortest single axiom for implicational S4—which to our knowledge is the first reported single axiom for that system—and several new shortest single axioms for implicational S5. A variety of automated reasoning strategies were essential to our discoveries.

A variety of robustness objections have been made against evolutionary game theory. One of these objections alleges that the games used in the underlying model are too arbitrary and oversimplified to generate a robust model of interesting prosocial behaviors. In this paper, I argue that the robustness objection can be met. However, in order to do so, we must attend to important conceptual issues regarding the nature of fairness, justice, and other moral concepts. Specifically, we must better understand the relationship (...) between moral concepts and formal characterizations of games. (shrink)

In numerous studies, experimental economists have documented the fact that people tend to propose that divisible goods be divided equally. It has often been proposed, most notably by the sociobiologists, that this tendency may have a biological basis, and might be the product of evolution and natural selection. ;My dissertation addresses methodological and philosophical problems that arise in the course of establishing this naturalistic claim. Specifically, the focus of this dissertation is on the project of using evolutionary game theory to (...) model the emergence of behavioral norms in a population. ;Chapter 1 briefly surveys the experimental economics literature that supports the existence of such behavioral propensities, and gives an overview of the dissertation. Chapter 2 introduces the fundamental concepts of game theory and evolutionary game theory. Chapter 3 argues that certain robustness failures may be overcome if group selection mechanisms are incorporated into the evolutionary models. Chapter 5 defends Peter Railton's causal theory of explanation, and argues that it best accommodates the dynamical models of evolutionary game theory. Chapter 6 addresses the question of whether a descriptive account of the origins of our moral intuitions is relevant to the normative project of identifying our moral obligations, and critiques arguments by Peter Singer and Peter Unger that our moral intuitions lack justification. (shrink)