Learning (Not) To Yield: An Experimental Study of Evolving Ultimatum Game Behavior

Whether behavior converges toward rational play or fair play in repeated ultimatum games depends on which player yields first. If responders concede first by accepting low offers, proposers would not need to learn to offer more, and play would converge toward unequal sharing. By the same token, if proposers learn fast that low offers are doomed to be rejected and adjust their offers accordingly, pressure would be lifted from responders to learn to accept such offers. Play would converge toward equal sharing. Here we tested the hypothesis that it is regret-both material and strategic-which determines how players modify their behavior. We conducted a repeated ultimatum game experiment with random strangers, in which one treatment does and another does not provide population feedback in addition to informing players about their own outcome. Our results show that regret is a good predictor of the dynamics of play. Specifically, we will turn to the dynamics that unfold when players make repeated decisions in the ultimatum game with randomly changing opponents, and when they learn not only about their own outcome in the previous round but also find out how the population on average has adapted to previous results (path dependence).Ultimatum bargaining game, Reputation, Regret, Learning, Experiment

Integrating forage technologies on smallholder farms in the upland tropics

In the past, adoption of forage technologies has been poor. This paper considers the reasons for this low level of adoption and how the situation has changed in recent years. Experiences, mostly in south-east Asia and some in east Africa, have shown that participatory approaches in the development of technology are the key to integration of forages into smallholder upland farming systems. This paper describes how projects went through the formal and informal stages of forage evaluation. Several key characteristics of communities were identified that determined whether forages could have an impact. A participatory approach was developed, which enhanced both forage technology development and its scaling-out to new areas. Some important data were generated on the environmental adaptation of forage varieties. A model for scaling-out forage technologies was developed. There are several stages of forage adoption, in which grass and legume species play different roles. Challenges for the future are to strengthen participatory approaches in the development of technology, especially in the process of scaling-out such developments