Context dependence and consistency in dynamic choice under uncertainty: the case of anticipated regret

We examine if and to what extent choice dispositions can allow dependence on contexts and maintain consistency over time, in a dynamic environment under uncertainty. We focus on one of the context dependence properties, opportunity dependence because of being affected by anticipated regret, where the consequentialist choice framework is maintained. There are two sources of potential inconsistency: one is arrival of information, and the other is changing opportunities. First, we go over the general method of resolution of potential inconsistency, by taking any kinds of inconsistency as given constraints. Second, we characterize a class of choice dispositions that are consistent to information arrival, but may be inconsistent to changing opportunities. Finally, we consider the overall requirement of dynamic consistency and show that it necessarily implies each of consistency to information arrival and independence of choice opportunities. The last result states that the two kinds of potential inconsistency cannot “compensate” each other to recover dynamic consistency overall.     

Naive,resolute or sophisticated? A study of dynamic decision making

Dynamically inconsistent decision makers have to decide, implicitly or explicitly, what to do about their dynamic inconsistency. Economic theorists have identified three possible responses—to act naively (thus ignoring the dynamic inconsistency), to act resolutely (not letting their inconsistency affect their behaviour) or to act sophisticatedly (hence taking into account their inconsistency). We use data from a unique experiment (which observes both decisions and evaluations) in order to distinguish these three possibilities. We find that the majority of subjects are either naive or resolute (with slightly more being naive) but very few are sophisticated. These results have important implications for predicting the behaviour of people in dynamic situations.

Dynamic Choice and NonExpected Utility

This paper explores how some widely studied classes of nonexpected utility models could be used in dynamic choice situations. A new "sequential consistency" condition is introduced for single-stage and multi-stage decision problems. Sequential consistency requires that if a decision maker has committed to a family of models (e.g., the multiple priors family, the rank-dependent family, or the betweenness family) then he use the same family throughout. Conditions are presented under which dynamic consistency, consequentialism, and sequential consistency can be simultaneously preserved for a nonexpected utility maximizer. An important class of applications concerns cases where the exact sequence of decisions and events, and thus the dynamic structure of the decision problem, is relevant to the decision maker. It is shown that for the multiple priors model, dynamic consistency, consequentialism, and sequential consistency can all be preserved. The result removes the argument that nonexpected utility models cannot be consistently used in dynamic choice situations. Rank-dependent and betweenness models can only be used in a restrictive manner, where deviation from expected utility is allowed in at most one stage.     

Are Groups More (or Less) Consistent Than Individuals?

There is now overwhelming experimental evidence that individuals systematically violate the axioms of Expected Utility theory. In reality, however, many economic decisions are taken by, or on behalf of, groups whose members have a joint stake in those decisions. This paper reports on an experiment in which pairs of individuals are tested for Common-Ratio inconsistencies. We find that the agreed choices of subject-pairs follow a pattern of inconsistency very close to that of individuals' choices. We also look for evidence that group participation increases the consistency of the individuals themselves. With one solitary exception, we find none.     

Sequential decision making without independence: a new conceptual approach

This paper presents a critical reflection on dynamic consistency as commonly used in economics and decision theory, and on the difficulty to test it experimentally. It distinguishes between the uses of the term dynamic consistency in order to characterize two different properties: the first accounts for the neutrality of individual preferences towards the timing of resolution of uncertainty whereas the second guarantees that a strategy chosen at the beginning of a sequential decision problem is immune to any reevaluation and will effectively be implemented from then on in the decision problem. Although these two properties are equivalent under expected utility (EU), this is not the case under non-EU. Building on the possible characteristics of individual dynamic preferences under risk, this paper proposes a conceptual categorization, that is experimentally testable, of possible sequential decision making behaviors of non-EU maximizers.     

印度战略文化及其变迁机制

自20世纪90年代战略文化成为备受关注的议题以来,从战略文化视角解释印度外交战略的研究不胜枚举.学术界对印度战略文化的研究普遍受到文化“稳定性”、“持久性”等基本特征的限制,主要从静止的视角围绕其起源、属性与形态等方面展开论述.本文试图从动态视角理解印度战略文化,构建战略文化生成与变迁理论框架.通过对战略文化的类型划分发现,印度在冷战时期形成了防御为主、进攻为辅的协调型战略文化,冷战后形成了强进攻性偏好的冲突型战略文化.作为印度战略文化变迁的首要条件,环境认知推动了印度国内政治程序的修正,从而影响了战略文化变迁.具体而言,国际体系环境的变化重塑了印度决策精英对国家安全的判断,并内化成新的观念体系.全新观念体系驱使决策精英行为偏好改变,且通过国内政治程序的修正上升为特定取向的国家战略偏好,最终生成全新的战略文化.     

Game Trees For Decision Analysis

Game trees (or extensive-form games) were first defined by von Neumann and Morgenstern in 1944. In this paper we examine the use of game trees for representing Bayesian decision problems. We propose a method for solving game trees using local computation. This method is a special case of a method due to Wilson for computing equilibria in 2-person games. Game trees differ from decision trees in the representations of information constraints and uncertainty. We compare the game tree representation and solution technique with other techniques for decision analysis such as decision trees, influence diagrams, and valuation networks.     

Decision settings analysis – a tool for analysis and design of human activity systems

The paper describes a methodology to be used for analysis and design of human activity systems. The methodology is based on an analysis of the decision settings whereas most other decision analysis methodologies are analysing the process. The decision concept is analysed and discussed. A distinction between programmed and programmable as well as non-programmed and non-programmable decisions is proposed. A classification of different information types for decision making is presented. A methodology based on a systemic and systematic analysis of the information requirements of an organization is proposed. This methodology also indicates organizational discrepancies and information imbalances. The methodology focuses the settings of the decisions on all levels of organizations. The methodology can be regarded as a dynamic, learning system. The author proposes further research on the individuals decision making abilities.     

A comparison of models for strategic planning,risk analysis and risk management

Summary Risks, uncertainties in firms and their environment are increasingly dealt with strategic planning, risk analysis and risk management. The present state of strategic planning enables us to consider the greatest part of internal and environmental risks mainly qualitatively - due to the fact that the majority of planning models used are of a deterministic type.The application of CAPM in strategic planning could take risks into account explicitly and maximize the expected value of the firms' common stock. Linked to a corporate simulation model or a DSS it could generate a series of values for the expected rate of return, its standard deviations as well as other output variables important for the management. The difficulties of the use of CAPM are numerous but an attempt to optimize the value of the firm would be a big step in developing new powerful instruments for evaluating the economic consequences of alternative strategies. The problems of CAPM lead to the considerations of the application of stochastic programming in strategic planning. For special cases solution methods can be developed and applied. The implementation of the Decision Support System in strategic planning could help to find the best decision in an interactive way - as suggested in this paper for the case of strategic marketing planning. DSS renders the consideration of other factors relevant to strategic decisions possible; businesses need not be reduced to portfolio terms. The limitations of CAPM, stochastic programming and the difficulties of the implementations of DSS for strategic planning could be partially avoided through the concept of Risk Management. On this concept strategic planning represents only one instrument of Risk Management and is a powerful tool of risk identification. In this paper the other instruments have been shortly demonstrated for the cases of product reliability and risks in relation with foreign countries. The development of new instruments for special cases (e.g., siting problems, specific strategic decisions, etc.), the considerations of risk behavior in individual, group and inter-organizational or even international decision making are now the main topics in the urgent task of research in risk management.     

Involvement of Ministries of Health in Health Service Coverage Decisions: Is England an Aberrant Case?

This article examines the involvement of ministries of health in making health service coverage decisions in Denmark, England, France and Germany. The study aims to inform debate in England about the feasibility of reducing perceived ministerial and bureaucratic ‘interference’ in decisions affecting the National Health Service, based on interviews with senior government officials and other health system stakeholders. Ministries of health differ in their involvement in health system governance and coverage decisions (‘the benefits package’), reflecting differences in institutional arrangements. In all four countries, organizations at arm's length or independent from government are either involved in providing technical advice to the ministry of health or have been mandated to take these decisions themselves. However, ministries of health occasionally intervene in the decision‐making process or ignore the advice of these organizations. The Department of Health in England is not an aberrant case, at least in relation to coverage decisions. Indeed, ministries of health in Denmark and France play a larger role in making these decisions. Public pressure, often amplified by the media, is a shared reason for ministerial and ministry involvement in all four countries. This dynamic may thus limit the feasibility of attempts to further separate the NHS from both the Department of Health and wider political pressures.     

The chain store paradox

The chain store game is a simple game in extensive form which produces an inconsistency between game theoretical reasoning and plausible human behavior. Well-informed players must be expected to disobey game theoretical recommendations.The chain store paradox throws new light on the well-known difficulties arising in connection with finite repetitions of the prisoners dilemma game. Whereas these difficulties can be resolved by the assumption of secondary utilities arising in the course of playing the game, a similar approach to the chain store paradox is less satisfactory.It is argued that the explanation of the paradox requires a limited rationality view of human decision behavior. For this purpose a three-level theory of decision making is developed, where decisions can be made on different levels of rationality. This theory explains why insight into the rational solution of a decision problem does not necessarily mean that the corresponding course of action will be taken.     

The Independence Postulate,Hypothetical and Called-off Acts: a further reply to Rabinowicz

The Independence postulate links current preferences between called-off acts with current preferences between constant acts. Under the assumption that the chance-events used in compound von Neumann-Morgenstern lotteries are value-neutral, current preferences between these constant acts are linked to current preferences between hypothetical acts, conditioned by those chance events. Under an assumption of stability of preferences over time, current preferences between these hypothetical acts are linked to future preferences between what are then and there constant acts. Here, I show that a failure of Independence with respect to current preferences leads to an inconsistency in sequential decisions. Two called-off acts are constructed such that each is admissible in the same sequential decision and yet one is strictly preferred to the other. This responds to a question regarding admissibility posed by Rabinowicz ([2000] Preference stability and substitution of indifferents: A rejoinder to Seidenfeld, Theory and Decision 48: 311–318 [this issue]).     

The role of multi-objective optimization in negotiation and mediation support

The paper reviews the methodology of multi-objective modeling and optimization used in decision support based on computerized analytical models (as opposed to logical models used in expert systems) that represent expert knowledge in a given field. The essential aspects of this methodology relate to its flexibility: modeling and optimization methods are treated not as goals in themselves but as tools that help a sovereign user (an analyst or a decision maker) to interact with the model, to generate and analyze various decision options, to learn about possible outcomes of these decisions. Although the applications of such methods in negotiation and mediation support is scarce yet, their flexibility increases essentially the chances of such applications. Various aspects of negotiation and mediation methods related to multi-objective optimization and game theory are also reviewed. A possible application of the MCBARG system for supporting negotiation related to the acid rain problem is briefly summarized.     

Equivalent decision trees and their associated strategy sets

The purpose of this paper is to examine the structure of individual decisions under uncertainty in extensive (i.e., decision-tree) form at a sufficient level of generality to encompass many traditional as well as novel criteria of general choice under uncertainty. Considerations both of structure and of strategic effect arise. In § 2 we define weak and strong forms of strategic equivalence of decision trees and describe partial-normalization procedures by which all economically defined complete pure strategies may be identified for the decider and for chance. In § 3 we examine characteristics of locally randomized, behavior strategies for the decider as the degree of normalization is varied, and we deduce useful properties of the function which specifies an outcome lottery for each behavior strategy of the decider in conjuction with a deterministic or stochastic selection by Chance. In § 4 we list a wide variety of choice criteria which may be invoked within the framework developed here.     

On Seidenfeld‘s Criticism of Sophisticated Violations of the Independence Axiom 1

An agent who violates independence can avoid dynamic inconsistency in sequential choice if he is sophisticated enough to make use of backward induction in planning. However, Seidenfeld has demonstrated that such a sophisticated agent with dependent preferences is bound to violate the principle of dynamic substitution, according to which admissibility of a plan is preserved under substitution of indifferent options at various choice nodes in the decision tree. Since Seidenfeld considers dynamic substitution to be a coherence condition on dynamic choice, he concludes that sophistication cannot save a violator of independence from incoherence. In response to McClennens objection that relying on dynamic substitution when independence is at stake must be question-begging, Seidenfeld undertakes to prove that dynamic substitution follows from the principle of backward induction alone, provided we assume that the agents admissible choices from different sets of feasible plans are all based on a fixed underlying preference ordering of plans. This paper shows that Seidenfelds proof fails: depending on the interpretation, it is either invalid or based on an unacceptable assumption.     

The 'Lombardy Model': Subsidiarity-informed Regional Governance

This article provides a concise overview of the Lombardy region's experience of government during the past twelve years. During this period, legislative, political and administrative strategic decisions have been informed by a distinctive vision, anchored in the principle of subsidiarity. The main characteristics of the emerging governance model are discussed: its political, juridical and social contexts; its underlying principles; its main policy goals, instruments and initiatives; and its criticalities and challenges.     

Consequentialist foundations for expected utility

Behaviour norms are considered for decision trees which allow both objective probabilities and uncertain states of the world with unknown probabilities. Terminal nodes have consequences in a given domain. Behaviour is required to be consistent in subtrees. Consequentialist behaviour, by definition, reveals a consequence choice function independent of the structure of the decision tree. It implies that behaviour reveals a revealed preference ordering satisfying both the independence axiom and a novel form of sure-thing principle. Continuous consequentialist behaviour must be expected utility maximizing. Other plausible assumptions then imply additive utilities, subjective probabilities, and Bayes' rule.     

Individual and group decision making under risk: An experimental study of Bayesian updating and violations of first-order stochastic dominance

This paper reports the results of experiments designed to test whether individuals and groups abide by monotonicity with respect to first-order stochastic dominance and Bayesian updating when making decisions under risk. The results indicate a significant number of violations of both principles. The violation rate when groups make decisions is substantially lower, and decreasing with group size, suggesting that social interaction improves the decision-making process. Greater transparency of the decision task reduces the violation rate, suggesting that these violations are due to judgment errors rather than the preference structure. In one treatment, however, less complex decisions result in a higher error rates.

Beyond Condorcet: optimal aggregation rules using voting records

In certain judgmental situations where a “correct” decision is presumed to exist, optimal decision making requires evaluation of the decision-makers’ capabilities and the selection of the appropriate aggregation rule. The major and so far unresolved difficulty is the former necessity. This article presents the optimal aggregation rule that simultaneously satisfies these two interdependent necessary requirements. In our setting, some record of the voters’ past decisions is available, but the correct decisions are not known. We observe that any arbitrary evaluation of the decision-makers’ capabilities as probabilities yields some optimal aggregation rule that, in turn, yields a maximum-likelihood estimation of decisional skills. Thus, a skill-evaluation equilibrium can be defined as an evaluation of decisional skills that yields itself as a maximum-likelihood estimation of decisional skills. We show that such equilibrium exists and offer a procedure for finding one. The obtained equilibrium is locally optimal and is shown empirically to generally be globally optimal in terms of the correctness of the resulting collective decisions. Interestingly, under minimally competent (almost symmetric) skill distributions that allow unskilled decision makers, the optimal rule considerably outperforms the common simple majority rule (SMR). Furthermore, a sufficient record of past decisions ensures that the collective probability of making a correct decision converges to 1, as opposed to accuracy of about 0.7 under SMR. Our proposed optimal voting procedure relaxes the fundamental (and sometimes unrealistic) assumptions in Condorcet’s celebrated theorem and its extensions, such as sufficiently high decision-making quality, skill homogeneity or existence of a sufficiently large group of decision makers.