基于不确定性约束条件的食物浪费行为研究*

本文探讨了决策者食物利用能力的不确定性如何引起食物浪费，并比较了食物浪费税和私人信息干预这两个政策工具对食物浪费量和社会福利的影响。研究结果表明，消费者食物最优保有量决策一旦偏离其食物利用能力，就会引发食物浪费。虽然两个政策工具都可以有效地降低食物浪费，但是食物浪费税对社会福利的影响方向不确定，而私人信息干预却可以通过激发学习机制增强决策者对自身食物利用能力的认知，并降低不确定性，从而提高整体社会福利。     

Half empty, half full and why we can agree to disagree forever

Aumann [Aumann R., 1976. Agreeing to disagree. Annals of Statisitics 4, 1236–1239] derives his famous we cannot agree to disagree result under the assumption that people are expected utility (=EU) decision makers. Motivated by empirical evidence against EU theory, we study the possibility of agreeing to disagree within the framework of Choquet expected utility (=CEU) theory which generalizes EU theory by allowing for ambiguous beliefs. As our first main contribution, we show that people may well agree to disagree if their Bayesian updating of ambiguous beliefs is psychologically biased in our sense. Remarkably, this finding holds regardless of whether people with identical priors apply the same psychologically biased Bayesian update rule or not. As our second main contribution, we develop a formal model of Bayesian learning under ambiguity. As a key feature of our approach the posterior subjective beliefs do, in general, not converge to “true” probabilities which is in line with psychological evidence against converging learning behavior. This finding thus formally establishes that CEU decision makers may even agree to disagree in the long-run despite the fact that they always received the same information.     

A two-person game of information transmission

We consider a statistical decision problem faced by a two player organization whose members may not agree on outcome evaluations and prior probabilities. One player is specialized in gathering information and transmitting it to the other, who takes the decision. This process is modeled as a game. Qualitative properties of the equilibria are analyzed. The impact of improving the quality of available information on the equilibrium welfares of the two individuals is studied. Better information generally may not improve welfare. We give conditions under which it will.     

Present bias and the inefficiency of the centralized economy: The role of the elasticity of intertemporal substitution

We analyze an endogenous growth model considering agents with an isoelastic utility. Preferences are characterized by a utility affected by a negative externality, and a level of impatience which decays with the time distance from the present. Agents who cannot commit the actions of their future selves, play a game against them. The stationary equilibrium of this game defines a balanced growth path with a slower growth when played by subsequent central planners than when played by decision makers in the market economy. First, we prove that the fast growing market economy implies higher welfare if the negative externality is small, while the centralized economy is welfare improving above a given threshold for the externality (obtained for a specific family of non-constant discount functions). Secondly, we observe that this threshold increases with the elasticity of intertemporal substitution in consumption. Therefore, the greater this elasticity the more likely it is that the externality lies below this threshold, where policy interventions would not be adequate. Finally, as one would expect, the range of values of the externality for which the market equilibrium provides higher welfare widens the more different from constant discounting time preferences are, due either to a wider range of variation for the instantaneous discount rates or because these decay more slowly.     

Hedonic adaptation and the role of decision and experience utility in public policy

Many economists are becoming supportive of ‘soft’ paternalistic interventions that help people to avoid common decision errors without curtailing individual autonomy. To identify when such interventions could be beneficial, and to assess their success, requires a welfare criterion. However, traditional preference or choice-based criteria cannot serve this function because they assume that whatever people choose makes them better off. An alternative criterion that bases welfare on happiness rather than choice avoids this problem but has several of its own drawbacks. Most notably, people often adapt to serious chronic health conditions, and exhibit high levels of happiness, even though both those with and those without the condition agree that it is much preferable to be healthy. After reviewing different lines of research that shed light on the pros and cons of these alternative welfare criteria, we argue that no simple criterion based on either concept can surmount these problems. Instead, evaluations of welfare will inevitably have to be informed by a combination of both approaches, patched together in a fashion that depends on the specific context.     

Desirability bias in foresight: Consequences for decision quality based on Delphi results

In foresight activities uncertainty is high and decision makers frequently have to rely on human judgment. Human judgment, however, is subject to numerous cognitive biases. In this paper, we study the effects of the desirability bias in foresight. We analyze data from six Delphi studies and observe that participants systematically estimate the probability of occurrence for desirable (undesirable) future projections higher (lower) than the probability for projections with neutral desirability. We also demonstrate that in the course of a multi-round Delphi process, this bias decreases but is not necessarily eliminated. Arguably, the quality of decisions based on Delphi results may be adversely affected if experts share a pronounced and common desirability for a future projection. Researchers and decision makers have to be aware of the existence and potential consequences of such a desirability bias in Delphi studies when interpreting their results and taking decisions. We propose a post-hoc procedure to identify and quantify the extent to which the desirability bias affects Delphi results. The results of this post-hoc procedure complement traditional Delphi results; they provide researchers and decision makers with information on when and to which extent results of Delphi-based foresight may be biased.     

Anti-herding and strategic consultation

In this paper I analyze how careerist decision makers aggregate and use information provided by others. I find that decision makers who are motivated by reputation concerns tend to ‘anti-herding’, i.e., they excessively contradict public information such as the prior or others’ recommendations. I also find that some decision makers may deliberately act unilaterally and not consult advisers although advice is costless. Moreover, advisers to the decision maker may not report their information truthfully. Even if the advisers care only about the outcome, they bias their recommendation since they anticipate inefficient anti-herding behavior by the decision maker.     

损失规避与经济波动的福利成本研究

目前经济波动的福利成本研究均建立在基于消费的效用函数基础上，而引入收入波动后我们发现：收入波动导致的福利成本才是更为重要的因素。本文定义的偏好具有损失规避的特点，在比较温和的参数设定下，考虑了收入波动后得到的福利成本指标A在1．4％--13．4％之间，比此前各种技术方法得到的A值提高了1—2个数量级。采用中国转型期以来的统计数据，消除短期波动的福利效果等同于将消费的长期增长率再提高约0．25个百分点，这表明如能进一步稳定经济的运行，仍会带来可观的福利提升。     

The product market opportunity loss of mandated disclosure

In the interests of protecting decision makers in the financial markets, the Securities and Exchange Commission requires publicly traded companies to publicly disclose certain accounting information. Such disclosure requirements however create a potential opportunity loss. They may destroy firms’ opportunities for implementing an alternative information acquisition and exchange regime – one that would optimize the firms’ product market profits. Nevertheless, we show that despite the previous imposition of an opportunity loss, firms may still favor future increased disclosure requirements. Finally, when information cost declines, although firms’ welfare may decrease, their desire for increased disclosure requirements always strengthens.     

Service Quality,Competition, and Regulatory Policies in the Postal Sector

This paper presents a simple model which illustrates the possible policy- and welfare-implications of endogenous product selection in the postal sector. The cost of a unit of mail depends on its "quality" (e.g., speed of delivery) and on the type and location of the addressee (firms, urban households, and rural households). Senders have inelastic demands and differ in their willingness to pay for quality. Addressees are passive but their utility may affect social welfare. Two operators play a two-stage game, first choosing qualities and then prices. We first show that the equilibrium with two private (profit maximizing) operators results in an inefficient provision of quality. Then, we consider the mixed (Nash) equilibrium with one private and one (welfare maximizing) public operator. If the budget constraint of the public firm is not binding, this equilibrium is shown to be first-best efficient even if social welfare accounts for the utility of addressees. If the budget constraint is binding, the mixed equilibrium is not efficient but yields a higher level of welfare than the private equilibrium. Finally, we study the impact of minimum quality standards within our setting.     

Who follows the crowd—Groups or individuals?

In games of social learning individuals tend to give too much weight to their own private information relative to the information that is conveyed by the choices of others (Weizsäcker, 2010). In this paper we investigate differences between individuals and small groups as decision makers in information cascade situations. In line with results from social psychology as well as results on Bayesian decision making (Charness et al., 2006) we find that groups behave more rationally than individuals. Groups, in particular, are able to abandon their own private signals more often than individuals when it is rational to do so. Our results indicate that the intellective part of the decision task contributes slightly more to the superior performance of groups than the judgmental part. Our findings have potential implications for the design of decision making processes in organisations, finance and other economic settings.     

On the demand for information

Most previous research on the economics of information has been based on the expected utility hypothesis and Bayesian learning. Yet there is experimental evidence that decision makers do not always maximize expected utility and that human learning is not always consistent with Bayes' rule. Using a two-period model, this paper examines the valuation of information as well as the demanf for information in the broader context of a state preference approach under an ordinal representation of preferences. In particular, it is not assumed that the decision maker is Bayesian, nor that he behaves in a way consistent with the expected utility hypothesis. In this general framework, the value of information is defined and analysed. Also, under active learning, the optimal allocation of information gathering activities is discussed. Behavioural properties of the demand for information are derived making use of a compensation function. Implications of the results for measuring the value of information and for the economic analysis of learning activities are discussed.     

Intergenerational transfers,demographic transition,and altruism: Problems in developing Asia

This paper develops a three‐period overlapping‐generations model where middle‐aged agents care about not only their own lifetime utility but also their old parents' and children's well‐being. The doubly altruistic agents choose amounts of intergenerational transfers to their old parents and children as well as private savings. The government specifies amounts of public transfers from working adults to the dependents. The model also takes the effects of demographic transition on the burdens of supporting the elderly and children into account. Using 23 countries' data from the National Transfer Accounts (NTA ), we estimate the degrees of filial and parental altruism and adjust them for their respective life expectancy and fertility rates. The findings suggest that people in developing countries are more parentally altruistic than those in developed ones while the adjusted degree of filial altruism tends to be low in developing Asia. Our welfare analyses reveal that the developing Asian countries must introduce more comprehensive public welfare programs for the elderly to maximize social welfare. Moreover, their low adjusted degree of filial altruism may trap the developing Asian countries at the low levels of public old‐age support and social welfare as the further demographic transition ensues.     

Aggregation of binary evaluations with abstentions

A general model of aggregation of binary evaluations over interrelated issues, introduced by Wilson and further studied by Rubinstein and Fishburn and by the authors, is extended here to allow for abstentions on some of the issues. It is shown that the same structural conditions on the set of feasible evaluations that lead to dictatorship in the model without abstentions, lead to oligarchy in the presence of abstentions. Arrow's impossibility theorem for social welfare functions, Gibbard's oligarchy theorem for quasi-transitive social decision functions, as well as some apparently new theorems on preference aggregation, are obtained as corollaries.     

The trend of welfare disparity among subgroups of population in Australia 1983-1984 - 1993-1994

The aim of this paper is to estimate the trend of social welfare for Australia using 1983–1984, 1988–1989 and 1993–1994 Household Expenditure Survey data. The functional form of the Social Welfare Function (SWF) was derived by Sen, Degum, Yitzhaki and Shesinski (all independently). Since the function contains the Gini coefficient as the inequality parameter, it could not be formally disaggregated by subgroups of population. This paper, using a method of subgroup decomposition of the Gini coefficient developed by Podder, attempts to disaggregate the SWF. With this method it is now possible to identify disadvantaged groups by their relative shares in total welfare. In addition the method is used to determine effect of economic growth on specific subgroups, and in turn, on total social welfare. This study is based on the Australian economy. Distribution of relative shares of total social welfare among various regional groups are identified, groups determined by occupational status and groups determined by country of birth. The effect on society's welfare for a percentage change in income of a group and the trend of relative welfare of a specific group are also computed. This information can be used in a variety of social decision making situations, including cost benefit analysis.     

Should refusal to sell be illegal?

We analyse a private firm's decision of whether to refuse to sell to a particular group of consumers whose interaction with other consumers generates negative externalities. The literature has rarely incorporated this motive directly into the firm's profit-maximisation problem. Discriminatory refusal-to-sell policies can increase profits and consumer utility among those affected by the negative externality. Of course it also reduces utility among consumers who are refused, raising the possibility of an indeterminate effect on social welfare. We obtain a stark and rather surprising result: The refusal-to-sell policy is socially optimal whenever it is individually optimal for a profit-maximising firm to adopt such a policy. No legislation or regulation is required from a social-welfare perspective (under the assumptions used in the specification of the social welfare function). We prove this result analytically for the case of linear demand functions. Numerical simulations show that the result also holds for constant-price-elasticity demand functions.     

Specifications of Social Welfare in Economic Studies of Climate Policy: Overview of Criteria and Related Policy Insights

An important assumption in economic studies of climate policy is the social welfare function. This paper shows that applying distinct decision or social welfare criteria can result in different optimal policies of climate control, notably if climate change impacts are uncertain. First, decision criteria in current climate-economic studies are reviewed. Next, the most important alternatives are discussed, including their (mathematical) formalization and incorporation in economy-climate models. Most of these alternative criteria suggest more stringent climate policies to be optimal than the standard discounted utilitarianism approach. However, several important welfare criteria have not or hardly seen any application in the economic analysis of climate policy. We conclude that there is clear need for systematic research on this theme, for which the current review provides a solid basis.     

Subject Perceptions of Confidence and Predictive Validity in Financial Information Cues

Traditional financial theory holds that financial decision makers make choices based on an asset's mean return and its standard deviation in the context of the normal distribution. These statistics, however, may be vague concepts to decision makers, and more difficult to use relative to specific details of a simple discrete probability distribution. Therefore, this study shows which of ten information cues subjects use in making decisions designed to look like simplified bonds, stocks, and options. The cues consist of the mean, standard deviation, and other distribution features such as highest payoff. More importantly, this study relates subjects' usage of various information cues in making financial valuation judgments to their self-assessments of 1) an information cue's ability to best reveal the value of an asset (its predictive validity), and 2) their confidence in using that information cue. The results are related to the overconfidence literature in psychology.     

Continuous linear representability of binary relations

Summary A very general result on continuous linear representability of binary relations on topological vector spaces is presented. Applications of this result include individual decision making under uncertainty, i.e. expected utility theory and collective decision making, in particular, utilitaristic social welfare functions.Thanks are due for helpful comments to Manfred Nermuth, David Schmeidler, Antonio Villar, and anonymous referees. Financial support from the DFG under Tr 120/4-2 is gratefully acknowledged.     

Monetary Policy Committees: Individual and Collective Reputations

This paper looks at the incentives of individual members of a monetary policy committee to gain a reputation for inflationary toughness. I show a policy maker can have more or less incentive to build a reputation when part of a group. But, group policy making leads to higher expected social welfare. Not publishing individuals' votes, raises the temptation to inflate and lowers expected social welfare. If the culture or rules of a central bank puts more weight on senior policy makers, the incentive to build a reputation is greater, but expected social welfare may be higher or lower.