Awareness and partitional information structures

This is the first of two papers where we present a formal model of unawareness. We contrast unawareness with certainty and uncertainty. A subject is certain of something when he knows that thing; he is uncertain when he does not know it, but he knows he does not: he is consciously uncertain. On the other hand, he isunaware of something when he does not know it, and he does not know he does not know, and so on ad infinitum: he does not perceive, does not have in mind, the object of knowledge. The opposite of unawareness is awareness, which includes certainty and uncertainty.This paper has three main purposes. First, we formalize the concept of awareness, and introduce a symmetry axiom which states that a subject can be aware of something, say, if and only if he is aware of its negation not-; in other words, that and not- are perceived together, or neither is. We then derive the basic properties of awareness.The second purpose is to prove a different axiomatic characterization, based on the concept of awareness of the system which underlies the model of information with partitional structures (known asS5).The third purpose of this paper is to show that without a substantial weakening of the rules of inferences normally assumed in modal logic a satisfactory model of unawareness, which includes the symmetry axiom, is impossible. This alternative approach is developed in a second paper by the same authors.     

Does exposure to unawareness affect risk preferences? A preliminary result

One fundamental assumption often made in the literature on unawareness is that risk preferences are invariant to changes of awareness. We study how exposure to unawareness affects choices under risk. Participants in our experiment choose repeatedly between varying sure outcomes and a lottery in three phases. All treatments are exactly identical in phase 1 and phase 3, but differ in phase 2. There are five different treatments pertaining to the lottery faced in phase 2: The control treatment (i.e., a standard lottery), the treatment with awareness of unawareness of lottery outcomes but known number of outcomes, the treatment with awareness of unawareness of outcomes but with unknown number of outcomes, the treatment with unawareness of unawareness of some outcomes, and the treatment with an ambiguous lottery. We study both whether behavior differs in phase 3 across treatments (between subjects effect) and whether differences of subjects’ behavior between phases 1 and phase 3 differ across treatments (within subject effects). We observe no significant treatment effects.     

Multi-task agency with unawareness

The paper introduces the problem of unawareness into multi-dimensional Principal–Agent theory. We introduce two key parameters to describe the problem, the extent and the effect of unawareness, show under what conditions it is optimal for the Principal to propose an incomplete or a complete contract, and characterize the incentive power of optimal linear contracts. If Agents differ in their unawareness, optimal incentive schemes can be distorted for both aware and unaware Agents, because, different from standard contract theory, the single-crossing property fails to hold. In this case, even aware Agents can be subject to inefficiently high or low incentives.     

Trust, inequality and the market

This article examines, experimentally, whether inequality affects the social capital of trust in non-market and market settings. We consider three experimental treatments, one with equality, one with inequality but no knowledge of the income of other agents, and one with inequality and knowledge. Inequality, particularly when it is known, has a corrosive effect on trusting behaviours in this experiment. Agents appear to be less sensitive to known relative income differentials in markets than they are in the non-market settings, but trust in markets appears generally more vulnerable to the introduction of inequality than in the non-market setting.     

The Ecology of Risk Taking

We analyze the risk level chosen by agents who have private information regarding their quality. We show that even risk-neutral agents will choose risk strategically to enhance their reputation in the market, and that such choices will be influenced by the mix of other agents' types. Assuming that the market has no strong prior about whether the agents are good or bad, good agents will choose low levels of risk, and bad agents high levels. Empirical evidence is gathered on 2462 firms over 24 years. The results support the model: agents of higher quality have less variable performance.     

Solomonic separation: Risk decisions as productivity indicators

A principal provides budgets to agents (e.g., divisions of a firm or the principal’s children) whose expenditures provide her benefits, either materially or because of altruism. Only agents know their potential to generate benefits. We prove that if the more “productive” agents are also more risk-tolerant (as holds in the sample of individuals we surveyed), the principal can screen agents and bolster target efficiency by offering a choice between a nonrandom budget and a two-outcome risky budget. When, at very low allocations, the ratio of the more risk-averse type’s marginal utility to that of the other type is unbounded above (e.g., as with CRRA), the first-best is approached.—A biblical opening enlivens the analysis.     

Equilibria with vector-valued utilities and preference information. The analysis of a mixed duopoly

This paper deals with the equilibria of games when the agents have multiple objectives and, therefore, their utilities cannot be represented by a single value, but by a vector containing the various dimensions of the utility. Our approach allows the incorporation of partial information about the preferences of the agents into the model, and permits the identification of the set of equilibria in accordance with this information. We also propose an additional conservative criterion which can be applied in this framework in order to predict the results of interaction. The potential application of the theoretical results is shown with an analysis of a mixed oligopoly in which the agents value additional objectives other than their own benefit. These objectives are related to social welfare and to the profit of the industry. The flexibility of our approach provides a general theoretical framework for the analysis of a wide range of strategic economic models.     

No Switchbacks: Rethinking Aspiration-Based Dynamics in the Ultimatum Game

Aspiration-based evolutionary dynamics have recently been used to model the evolution of fair play in the ultimatum game showing that incredible threats to reject low offers persist in equilibrium. We focus on two extensions of this analysis: we experimentally test whether assumptions about agent motivations (aspiration levels) and the structure of the game (binary strategy space) reflect actual play, and we examine the problematic assumption embedded in the standard replicator dynamic that unhappy agents who switch strategies may return to a rejected strategy without exploring other options. We find that the resulting “no switchback” dynamic predicts the evolution of play better than the standard dynamic and that aspirations are a significant motivator for our participants. In the process, we also construct and analyze a variant of the ultimatum game in which players can adopt conditional (on their induced aspirations) strategies.     

The notion of character friendship and the cultivation of virtue

Most theories about virtue cultivation fall under the general umbrella of the role model approach, according to which virtue is acquired by emulating role models, and where those role models are usually conceived of as superior in some relevant respect to the learners. I argue that although we need role models to cultivate virtue, we also need good and close relationships with people who are not our superiors. The overemphasis on role models is misguided and misleading, and a good antidote draws on the Aristotelian concept of character friendship. Character friendship (a) constitutes a unique form of experience in which we share a substantial way of seeing with a close other; (b) facilitates a unique form of knowledge, the knowledge of a particular person (my‐self and the other's self); (c) develops other emotions important for virtue cultivation besides admiration, such as love, shame, trust, and hope; and (d) is a praxis in which cooperative interactions and discussions function as a bridge between habituation of virtue at home and the public life. Character friendship provides necessary elements for human cultivation of virtue that the sole experience of having a role model does not.     

Maintaining Environmental Resources in the International System: A Comparison of Contractual Arrangements

Objectives. State A may control an environmental resource that has value for other actors in the international system. The objective of this article is to compare different contractual arrangements between State A and other agents for preservation of this resource. I concentrate on direct purchase schemes and dynamic (stream–of–payment) schemes. Methods. The problem is analyzed by constructing a model of the returns to State A from exploiting the resource; its public goods value; and transfer payments from other agents. Results. Among the main results are that continual transfers may be better than a one–off buyout and, if the resource does not have a public goods value for the owner, compensation may not be effective. Conclusions. Generally, the analysis points out the gains to be made from paying attention to the type of contractual arrangement. Most of these results would not have been intuitively clear. I also show that rental schemes may be the least risky option.     

Macroeconomic effects of an open-ended asset purchase programme

We evaluate the effectiveness of an open-ended asset purchase programme (APP) using a New Keynesian model of euro area. We assume that the central bank does not announce the ending date of the programme, and agents form their expectations about possible additional purchases beyond the horizon of the announcement according to the central bank reaction function, that links the purchases to the expected inflation gap. It is showed that the open-ended APP is more effective in stimulating macroeconomic conditions than committing ex ante to an ending date.     

秦岭品牌与陕南旅游的区域协作发展策略

基于陕南旅游的健康快速发展目标,提出了秦岭旅游品牌概念并对其文化内涵、整体优势和区域协作方略等进行了研究和论述。在分析陕南旅游对于秦岭品牌认识不到位、概念不清晰、缺少创意性和推广意识等问题的基础上,指出秦岭品牌应该更好地统领陕南旅游业的规划与建设,并促使陕西省的旅游内涵更加丰富、旅游产业链更加完善。     

Intentional Exposure Studies of Environmental Agents on Human Subjects: Assessing Benefits and Risks∗

In this article, I assess the benefits and risks of studies that intentionally expose research subjects to environmental agents. I describe these types of studies, identify their benefits and risks, compare them to other research methods that can be used to investigate the relationship between environmental exposures and disease, and discuss some issues related to research design and risk minimization. I argue that the benefits of intentional environmental exposure studies outweigh the risks when 1) the knowledge gained is likely to improve our understanding of the relationship between environmental exposure and disease, 2) this knowledge cannot be obtained by other methods, 3) the experiments are well designed, 4) the subjects will receive some benefits, such as medical evaluations, 5) risks are minimized, and 6) the risks to human subjects are less than those encountered in a typical Phase I drug study. Only in rare circumstances (i.e., when an intentional environmental exposure study is needed to implement an important environmental or public health intervention or regulation) may such studies expose research subjects to risks as high as those encountered in a typical Phase I drug trail.     

Intentional exposure studies of environmental agents on human subjects: assessing benefits and risks

In this article, I assess the benefits and risks of studies that intentionally expose research subjects to environmental agents. I describe these types of studies, identify their benefits and risks, compare them to other research methods that can be used to investigate the relationship between environmental exposures and disease, and discuss some issues related to research design and risk minimization. I argue that the benefits of intentional environmental exposure studies outweigh the risks when 1) the knowledge gained is likely to improve our understanding of the relationship between environmental exposure and disease, 2) this knowledge cannot be obtained by other methods, 3) the experiments are well designed, 4) the subjects will receive some benefits, such as medical evaluations, 5) risks are minimized, and 6) the risks to human subjects are less than those encountered in a typical Phase I drug study. Only in rare circumstances (i.e., when an intentional environmental exposure study is needed to implement an important environmental or public health intervention or regulation) may such studies expose research subjects to risks as high as those encountered in a typical Phase I drug trail.     

Risk aversion in expected intertemporal discounted utilities bandit problems

We consider a situation where an individual is facing an uncertain situation, but may costly alter his knowledge of the uncertainties. We study in this context how risk aversion may modify the individual search behavior. We consider a one-armed bandit problem (where one arm is safe and the other is risky) and study how the agent risk aversion can change the sequence of arms selected. The main result is that when the utility function is more concave, the agent has more chances to select the safe arm. We also discuss how search is affected by risk aversion.     

Learning under compound risk vs. learning under ambiguity – an experiment

We design and conduct an economic experiment to investigate the learning process of agents under compound risk and under ambiguity. We gather data for subjects choosing between lotteries involving risky and ambiguous urns. Agents make decisions in conjunction with a sequence of random draws with replacement, allowing us to estimate the agents’ beliefs at different moments in time. For each type of urn, we estimate a behavioral model for which the standard Bayesian updating model is a particular case. Our findings suggest an important difference in updating behavior between risky and ambiguous environments. Specifically, even after controlling for the initial prior, we find that when learning under ambiguity, subjects significantly overweight the new signal, while when learning under compound risk, subjects are essentially Bayesian.     

西北普通高校大学生体育锻炼意识与运动兴趣的调查研究

通过对西北普通高校大学生体育锻炼意识、健康状况与运动兴趣调查分析表明 :大学生喜欢上体育的人数不到 6 0 % ,相当一部分学生对体育的健身价值缺乏正确的认识 ,没有体育锻炼的习惯和意识 ;学生的体质健康状况不理想 ,必须引起有关领导的重视 ;学生对健身类、健美类、娱乐兴和球类体育活动比较感兴趣 ,学校应多为学生提供这方面的教学和活动场所。     

Planning in firms as an interactive process

This paper discusses the possible uses of economic analysis for strategic planning decisions in firms. It proposes an approach which emphasizes the role of common knowledge for decentralized parallel decision processes. Planning is interpreted as an interactive process among a set of agents who use a plan to formalize a theory of action and an invalidating procedure. In the course of action the agents are supposed to cope with uncertainty as long as the chosen theory remains justified. This approach has strong connections with some recent trends in managerial economics and in particular with the current work in the production sphere which similarly illuminates the role of common knowledge through objective physical flows to promote global efficiency of the firm.     

The PAYG system and the optimal redistribution instrument in an overlapping generation model

Using a two‐period overlapping generation (OLG) model, this article seeks to identify the optimal redistribution policy instrument in terms of aggregate welfare when agents differ according to their labour condition. We use five policy specifications: (i) early redistribution to the young informal generation; (ii) late redistribution to the informal old generation; (iii) a mix between early and late redistribution; (iv) redistribution from the current formal young generation to the current formal old one; and (v) a non‐redistribution scenario. With inelastic labour supply, we show that transferring to the young performs better as a redistribution policy. This result is robust across different parameter values.     

Competence effects for choices involving gains and losses

We investigate how choices for uncertain gain and loss prospects are affected by the decision maker’s perceived level of knowledge about the underlying domain of uncertainty. Specifically, we test whether Heath and Tversky’s (J Risk Uncertain 4:5–28, 1991) competence hypothesis extends from gains to losses. We predict that the commonly-observed preference for high knowledge over low knowledge prospects for gains reverses for losses. We employ an empirical setup in which participants make hypothetical choices between gain or loss prospects in which the outcome depends on whether a high or low knowledge event occurs. We infer decision weighting functions for high and low knowledge events from choices using a representative agent preference model. For gains, we replicate the results of Kilka and Weber (Manage Sci 47:1712–1726, 2001), finding that decision makers are more attracted to choices that they feel more knowledgeable about. However, for losses, we find limited support for our extension of the competence effect.