Team Incentives and Reference-Dependent Preferences

This paper examines a multi-agent moral hazard model in which agents have expectation-based reference-dependent preferences `a la K˝oszegi and Rabin (2006, 2007). The agents’ utilities depend not only on their realized outcomes but also on the comparisons of their realized outcomes with their reference outcomes. Due to loss aversion, the agents have a first-order aversion to wage uncertainty. Thus, reducing their expected losses by partially compensating for their failure may be beneficial for the principal. When the agent is loss averse and the project is hard to achieve, the optimal contract is based on team incentives which exhibit either joint performance evaluation or relative performance evaluation. Our results provide a new insight: team incentives serve as a loss-sharing device among agents. This model can explain the empirical puzzle of why firms often pay a bonus to low-performance employees as well as high-performance employees.Moral Hazard, Team Incentives, Reference-Dependent Preferences, Loss Aversion, Joint Performance, Evaluation, Relative Performance Evaluation

The Timing of Choice-Enhancing Policies

Recent studies investigate policies motivating consumers to make an active choice as a way to protect unsophisticated consumers. We analyze the optimal timing of such choice-enhancing policies when a firm can strategically react to them. In our model, a firm provides a contract with automatic renewal. We show that a policy intending to enhance consumers choices when they choose a contract can be detrimental to welfare. By contrast, a choice-enhancing policy at the time of contract renewal increases welfare more robustly. Our results highlight that policies should be targeted in timing to the actual choice inefficiency

Consumer Exploitation and Notice Periods

Firms often set long notice periods when consumers cancel a contract, and sometimes do so even when the costs of changing or canceling the contract are small. We investigate a model in which a firm offers a contract to consumers who may procrastinate canceling it due to naive present-bias. We show that the firm may set a long notice period to exploit naive consumers

Magnetic skyrmions and skyrmion clusters in the helical phase of Cu2_2OSeO3_3

Skyrmions are nanometric spin whirls that can be stabilized in magnets lacking inversion symmetry. The properties of isolated skyrmions embedded in a ferromagnetic background have been intensively studied. We show that single skyrmions and clusters of skyrmions can also form in the helical phase and investigate theoretically their energetics and dynamics. The helical background provides natural one-dimensional channels along which a skyrmion can move rapidly. In contrast to skyrmions in ferromagnets, the skymion-skyrmion interaction has a strong attractive component and thus skyrmions tend to form clusters with characteristic shapes. These clusters are directly observed in transmission electron microscopy measurements in thin films of Cu$_2$OSeO$_3$. Topological quantization, high mobility and the confinement of skyrmions in channels provided by the helical background may be useful for future spintronics devices.Comment: 5 pages, 3 figures, 4 pages supplemen

小学校における農業体験学習の活動内容とその教育的意義 : 学校農園型を中心とした分析

広島大学(Hiroshima University)博士(学術)Doctor of Philosophydoctora

Shame and Exculpation: Integration Modeling and Neuroimaging Approaches to Social Emotions

Imagine just winning the lottery. How much would you give to friends and acquaintances? Would your choice be different if no one knew you had just won? For many people, choices depend upon not only the material outcomes involved, but also on the beliefs and expectations of other people. Violation of these social expectations may result in negative emotions such as shame. Here we study behavior and neural responses to such expectations in the context of a simple economic game—the stochastic dictator game. In the game, a dictator chooses to allocate money between herself and an anonymous recipient while the pot of money available varies across rounds. Crucially, whereas the dictator always knows the pot size, the recipient can find out only with some probability. Behaviorally, we found that dictators gave more to the recipient when there was a greater likelihood of the recipient finding out the true pot size. In addition, subjects indicated a preference to hide the pot size from the recipient when it was large, but to reveal when the pot size was small. Using a model-based approach, we characterized subjects’ preferences as a weighted combination of material payoffs, payoff inequity, and the risk of being shamed. Functional neuroimaging showed that shame risk was negatively correlated with activity in the medial prefrontal cortex, whereas the relief of shame was positively correlated with activity in the striatum. Taken together, these results shed light on the cognitive processes underlying higher-order emotions, as well as their neural substrates