Naiveté and sophistication in dynamic inconsistency

This paper introduces a general framework for dealing with dynamic inconsistency in the context of Markov decision problems. It carefully decouples and examines concepts that are often entwined in the literature: it distinguishes between the decision maker and its various temporal agents, and between the beliefs and intentions of the agents. Classical examples of naiveté and sophistication are modeled and contrasted based on this new language. We show that naive and sophisticated decision makers can form optimal strategies at each possible history, and provide welfare comparisons for a class of decision problems including procrastination, impulsiveness, underinvestment, binges and indulgence. The creation of a unified formalism to deal with dynamic inconsistency allows for the introduction of a hybrid decision maker, who is naive sometimes, sophisticated at others. Such a hybrid decision maker can be used to model situations where type determination is endogenous. Interestingly, the analysis of hybrid types indicates that self-deception can be optimal

Building the Leviathan : voluntary centralisation of punishment power sustains cooperation in humans

The prevalence of cooperation among humans is puzzling because cooperators can be exploited by free riders. Peer punishment has been suggested as a solution to this puzzle, but cumulating evidence questions its robustness in sustaining cooperation. Amongst others, punishment fails when it is not powerful enough, or when it elicits counter-punishment. Existing research, however, has ignored that the distribution of punishment power can be the result of social interactions. We introduce a novel experiment in which individuals can transfer punishment power to others. We find that while decentralised peer punishment fails to overcome free riding, the voluntary transfer of punishment power enables groups to sustain cooperation. This is achieved by non-punishing cooperators empowering those who are willing to punish in the interest of the group. Our results show how voluntary power centralisation can efficiently sustain cooperation, which could explain why hierarchical power structures are widespread among animals and humans

The evolution of universal cooperation

Humans work together in groups to tackle shared problems and contribute to local club goods that benefit other group members. Whereas benefits from club goods remain group bound, groups are often nested in overarching collectives that face shared problems like pandemics or climate change. Such challenges require individuals to cooperate across group boundaries, raising the question how cooperation can transcend beyond confined groups. Here, we show how frequent intergroup interactions allow groups to transition from group-bound to universal cooperation. With frequent intergroup interactions, reciprocity of cooperative acts permeates group boundaries and enables the evolution of universal cooperation. As soon as intergroup interactions take place frequently, people start to selectively reward cooperation aimed at benefitting everyone, irrespective of their group membership. Simulations further show that it becomes more difficult to overcome group-bound cooperation when populations are fragmented into many small groups. Our findings reveal important prerequisites for the evolution of universal cooperation.Social decision makin

Beliefs, intentions, power : essays on dynamic decision problems

In this thesis individual and collective decision making is being researched. For individuals prone to procrastination or impulsivity, this work suggests that researchers and therapists should focus on the discrepancy between intentions and beliefs. For example, addicts could keep intention-belief diaries, where they specify how they want to behave, and how they think they will. Collective decision making is also intricate, as selfish free riders often take advantage of cooperative individuals’ efforts. This research shows that groups tend to select leaders who can force free riders to cooperate. Such self-organized hierarchies enable groups to achieve better outcomes

Optimal choice for finite and infinite horizons

This paper lays down conceptual groundwork for optimal choice in infinite-horizon finite-state Markov decision problems. We distinguish two notions of a strategy being favored on the limit of horizons, and examine the properties of the emerging binary relations. After delimiting two senses of optimality, we analyze the relationship between the resulting sets of optimal strategies - including the Ramsey-Weizsacker overtaking criterion - and their existence properties. We also relate to the pointwise limits of strategies of Fudenberg and Levine [3]