Social and Behavioral Sciences Commons^™

Let Me, Or Let George? Motives Of Competing Altruists, Ted Bergstrom, Rodney Garratt, Greg Leo

Ted C Bergstrom

Sometimes a costly action taken by a single individual is sufficient to benefit an entire group. This should imply technical economies of scale to groups of larger size. But in a group of selfishly motivated agents, a countervailing force, the free-rider problem, may actually reduce the likelihood of provision as group size increases. Yet there are con- spicuous real-world cases where, in seeming defiance of the free-rider problem, a small minority provides a public good that benefits a large population. Examples include unpaid contributions to Wikipedia, Linux, and the bone-marrow registry. We suggest that these successful outcomes occur because a …

Motivations Of Competing Altruists, Ted C. Bergstrom, Rodney Garratt, Gregory Leo

Ted C Bergstrom

This is a preliminary report on our experimental work with competing altruists.

Single-Payer Volunteers' Dilemma, Ted C. Bergstrom

Ted C Bergstrom

The "Volunteers' Dilemma model which was introduced by Andreas Diekmann is a game theoretic model of diffusion of responsibility where only one person is needed to perform a publicly beneficial act, but many people could do it. Players do not know what the others have done. In the symmetric mixed strategy Nash equilibrium for this game, the probability that nobody takes action increases as the number of players increases. This paper shows that the same result holds even when volunteers are taken anonymously but only one person is selected to perform the action/

The Good Samaritan And Traffic On The Road To Jericho, Ted C. Bergstrom

Ted C Bergstrom

One Chance In A Million: Altruism And The Bone Marrow Registry, Ted Bergstrom, Rod Garratt, Damien Sheehan-Connor

Ted C Bergstrom

Transplants of donated stem cells save the lives of many patients with blood diseases. Donation is somewhat painful, butrarely has lasting adverse effects. Patients can accept transplants only from donors with compatible immune systems. Those lacking a sibling match must seek donations from the population at large. The probability that two persons of the same race are compatible is less than 1/10,000. Health authorities maintain a registry of several million genetically-tested potential donors who have agreed to donate if asked. We study the peculiar structure of voluntary public good provision represented by the registry, and compare the marginal benefits and …

Natural Kantian Or Zoo Economicus? Evolutionary Theories Of Selfishness And Altruism Among Men And Beasts, Ted C. Bergstrom

Ted C Bergstrom

This paper addresses the question of whether our evolutionary history suggests that humans are likely to be individually selected selfish maximizers or group selected altruists. It surveys models from the literature of evolutionary biology in which groups are formed and dissolved and where the reproductive success of individuals is determined by their payoffs in a game played within groups. We show that if groups are formed randomly and reproductive success of group founders is determined by a multi-person prisoners’ dilemma game, then selfish behavior will prevail over maximization of group payoffs. However, interesting models can be found for which “group …

Benefit-Cost In A Benevolent Society, Ted Bergstrom

Ted C Bergstrom

How should benefit-cost analysis account for the value that benevolent individuals place on other people's pleasure from public goods? When adding up the benefits to be compared with costs, should we sum the private valuations, the altruistic valuations, or something else? This paper proposes a partial answer and offers some suggestions for benefit-cost practitioners.

The Iron Law Of Selfishness: Response To A Comment By Alexander Field, Ted Bergstrom

Ted C Bergstrom

Alexander Field was not convinced of a result that I claimed in my JEP 2001 paper that in "haystack models" with non-assortative mating, if the number of descendants of founding group members is determined by an n-player prisoners' dilemma game, then the population will converge to a population of defectors. He thought that the result applied only if the groups were large. I respond with a more detailed discussion and show how the result works even when groups have only two members.

Evolution Of Social Behavior: Individual And Group Selection, Ted Bergstrom

Ted C Bergstrom

How selfish does our evolutionary history suggest that humans will be? We explore models in which groups are formed and dissolved and where reproduction of individuals is determined by their payoffs in a game played within groups. If groups are formed ``randomly'' and reproductive success of group founders is determined by a multi-person prisoners' dilemma game, then selfish behavior will prevail over maximization of group payoffs. However, interesting models exist in which ``group selection'' sustains cooperative behavior. Forces that support cooperative behavior include assortative matching in groups, group longevity, and punishment-based group norms.

Does Mother Nature Punish Rotten Kids?, Ted Bergstrom, Carl Bergstrom

Ted C Bergstrom

The theory of parent-offspring conflict predicts that mothers and their offspring may not agree about how resources should be allocated among family members. A kid, for example, may favor a later weaning date than does its mother. Despite the mother's physical superiority, it may be that the kid is able to manipulate her behavior. In this paper, we investigate a two-locus population genetic model of weaning conflict in which offspring can attempt to extort resources from their parents by reducing their own chances of survival if their demands are not met. We find that the frequency of recombination between the …

On The Evolution Of Altruistic Ethical Rules For Siblings, Ted Bergstrom

Ted C Bergstrom

This paper explores the evolutionary foundations of altruism among siblings and extends biologists' kin-selection theory to a richer class of games between relatives. It shows that a population will resist invasion by dominant mutant genes if individuals maximize a "semi-Kantian" utility function in games with their siblings. It is shown that a population that resists invasion by dominant mutants may be invaded by recessive mutants. Conditions are found under which a population resists invasion by dominant and also by recessive mutants. (JEL C70, D10, D63)

How Altruism Can Prevail In An Evolutionary Environment, Ted Bergstrom, Oded Stark

Ted C Bergstrom

This paper considers a series of examples in which evolution supports cooperative behavior in single-shot prisoners' dilemma. Examples include genetic inheritance for asexual siblings and for sexual diploid siblings. We also study two models of ``cultural inheritance''; one in which siblings copy either their parents or an extrafamilial role model and one in which neighbors arrayed along a circular road copy successful neighbors. Finally, we consider a model in which parents choose their behavior, realizing that it may be imitated by their children. A unifying principle of these models is that cooperative behavior more is likely to be sustained in …