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.     

Ranking opportunity sets in a simple intertemporal framework

We extend the problem of ranking subsets (opportunity sets) of a set of alternatives to an intertemporal setting, whereby the agent makes a sequence of choice decisions over time. In particular, we show in a simple two-period model that an agent who satisfies five plausible axioms ranks opportunity sets in a lexicographic fashion. That is, the agent ranks opportunity sets based solely on the relative desirability of their first-period alternatives, and only if the first-period alternatives are thought equally desirable does the agent consider the second-period alternatives. We discuss this strong time-discounting result and the role of the axioms, and also show that the popular “independence” axioms employed in the existing “static” literature are inconsistent with some reasonable axioms regarding intertemporal choice.      

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.     

Delegation to a possibly ignorant agent

In a delegation problem, an uninformed principal delegates decision‐making powers to a biased and possibly ignorant agent. The principal cannot use monetary payments but can restrict the set of the agent's choices. I show that in the general case, the principal may offer a disconnected set of choices. In a setting with arbitrary bias the uncertainty principle holds—the principal benefits as the likelihood that the agent is informed increases. When the bias is constant, I show that the ally principle holds—the principal benefits as the bias becomes smaller. Finally, when the likelihood of the agent being informed is determined by the agent's effort, then for small biases the principal benefits from limiting the agent's choice. When the agent is sufficiently biased, the principal gives more choice to the agent, so as to to improve incentives for information acquisition.     

Status Quo Bias and the Number of Alternatives: An Empirical Illustration from the Mutual Fund Industry

We examine the extent of the status quo bias (SQB) in a real-world repeated decision situation. Individuals who are subject to the SQB tend to choose an alternative that they chose previously (i.e., their status quo), even if it is no longer the optimal choice. We examine the U.S. equity mutual fund market and find strong evidence of the SQB. Furthermore, the SQB is more severe in segments that have more funds to choose from. Thus, we deliver the first empirical confirmation of the experimental results of Samuelson and Zeckhauser [1988] that the SQB depends positively on the number of alternatives.     

HOW DELEGATING AUTHORITY BIASES SOCIAL CHOICES

Delegating authority can bias social choices. The bias derives from the persuasion process that accompanies social decision making. When decision makers can decide to delegate their authority, asymmetries in decision makers' persuasiveness and openness to persuasion can play an important role in distorting the outcomes of social choices. When permitted in social decision making, such ad hoc delegating may favor extreme points of view and may force more group decisions to formal, social-choice mechanisms such as voting.     

Coping with ignorance: unforeseen contingencies and non-additive uncertainty

Summary. In real-life decision problems, decision makers are never provided with the necessary background structure: the set of states of the world, the outcome space, the set of actions. They have to devise all these by themselves. I model the (static) choice problem of a decision maker (DM) who is aware that her perception of the decision problem is too coarse, as for instance when there might be unforeseen contingencies. I make a “bounded rationality' assumption on the way the DM deals with this difficulty, and then I show that imposing standard subjective expected utility axioms on her preferences only implies that they can be represented by a (generalized) expectation with respect to a non-additive measure, called a belief function. However, the axioms do have strong implications for how the DM copes with the type of ignorance described above. Finally, I show that some decision rules that have been studied in the literature can be obtained as a special case of the model presented here (though they have to be interpreted differently). Received: December 16, 1999; revised version: March 22, 2000     

AN OPTIMAL TAX TREATMENT OF LEVIATHAN*

This paper constructs a model in which taxation and public expenditure decisions are made by two decision makers: a “benevolent planner,” who treats all consumers equally in the measurement of welfare; and a “Leviathan planner,” who places more weight on the utilities of “favored consumers.” The benevolent planner can restrict the Leviathan planner's power to tax, but cannot control the allocation of expenditures between desirable public goods and income transfers to favored consumers. Several types of tax restrictions are shown to be welfare-improving from the benevolent planner's viewpoint. These restrictions include a reduction in the size of the tax base, although administrative costs already prevent the Leviathan planner from taxing all commodities.     

Measuring dispositions for lexicographic preferences of environmental goods: integrating economics,psychology and ethics

This paper combines the psychometric methods of paired comparisons (PC) and environmental disposition measurement to assist in identifying lexicographic behavior in choice experiments. Our methodology obtains complete preference profiles of all elements in the choice set and measures of attitudinal dispositions, including an environmental ethics (EE) disposition, for all respondents. The methodology is applied across two treatments that differ only on the range of the dollar magnitudes—Treatment A ranges from $10 to $700 (USD) and Treatment B ranges from $10 to $9000 (USD). Dispositions of pastoralism (PA), antiquarianism and environmental ethicism tend to correlate positively with increasing preferences for environmental goods, while the disposition of environmental adaptation (EA) negatively correlates with preferences for environmental goods. The marginal effects of environmental dispositions are largest for respondents who do not value environmental goods highly (low valuers) and those who potentially value the goods lexicographically. The results demonstrate that information regarding our sample's attitudinal dispositions toward the environment may enable the differentiation of high valuers from lexicographic valuers of environmental goods.     

Lexicographic choice under variable capacity constraints

In several matching markets, to achieve diversity, agents' priorities are allowed to vary across an institution's available seats, and the institution is let to choose agents in a lexicographic fashion based on a predetermined ordering of the seats, called a (capacity-constrained) lexicographic choice rule. We provide a characterization of lexicographic choice rules and a characterization of deferred acceptance mechanisms that operate based on a lexicographic choice structure under variable capacity constraints. We discuss some implications for the Boston school choice system and show that our analysis can be helpful in applications to select among plausible choice rules.     

ASSESSING THE VALUE OF ECONOMICS RESEARCH: THE CASE OF THE BIAS IN THE CONSUMER PRICE INDEX

Economists provide sometimes contradictory information about economic systems that contribute to policy design. How does one value this type of knowledge? A political‐economic game is presented that allows for reinforcing and contradictory research messages. Policy makers are assumed to follow a Bayesian decision theory process and the model is tested with quantitative estimates of the value of research on the degree of bias in the Consumer Price Index. Most economists agree that a bias exists, but published estimates vary widely. A blue‐ribbon panel of economists recommended revisions to how the index is calculated, and the Bureau of Labor Statistics subsequently made revisions that differed from their original plans, but how much influence did the panel really have on the revisions? (JEL Z00)     

An axiomatic definition of the leximin

For a class of multicriterion decision making problems the set of lexicographic minimax in a set of alternatives with regard to the given criterion functions is characterized by six axioms: symmetry, independence of irrelevant alternatives, domination, separability, convexity, and monotone transformation. Each of the axioms is independent of the rest.     

Evolutionary stability and lexicographic preferences

We explore the interaction between evolutionary stability and lexicographic preferences. To do so, we define a limit Nash equilibrium for a lexicographic game as the limit of Nash equilibria of nearby games with continuous preferences. Nash equilibria of lexicographic games are limit Nash equilibria, but not conversely. Modified evolutionarily stable strategies (Binmore and Samuelson, 1992. J. Econ. Theory 57, 278–305) are limit Nash equilibria. Modified evolutionary stability differs from “lexicographic evolutionarily stability” (defined by extending the common characterization of evolutionary stability to lexicographic preferences) in the order in which limits in the payoff space and the space of invasion barriers are taken.     

The separability axiom and equal-sharing methods

A quasi-linear social choice problem is defined as selecting one (among finitely many) indivisible public decision and a vector of monetary transfers among agents to cover the cost of this decision. This decision is based upon individual preferences, which are assumed to be additively separable and linear in money. The Separability axiom is a consistency property for choice methods on societies with variable size: the decision is not affected if we remove an arbitrary agent under the condition that he be guaranteed his original utility level and the cost to the remaining agents is modified accordingly. Thus the utility level assigned by the social choice function to agent i is the price at which the other agents are unanimously willing to buy agent is share of the decision power. A general characterization of choice methods satisfying this axiom is provided. Three subclasses of particular interest are characterized by additional milder axioms. Those are: (i) equal sharing of the surplus left over some reference utility (e.g., the utility at a status quo decision), (ii) utilitarian methods that merely select the efficient public decision and perform no monetary transfers, and (iii) equal allocation of nonseparable costs, which divides equally the surplus left over from the utility derived from the pivotal mechanism (also known as the Vickrey-Clarke-Groves mechanism).     

Participation, decision aggregation and internal information gathering in organizational decision making

This paper proposes a stylized theory that focuses on the determination of the structure of decision making within teams. This structure consists of two elements: the allocation of decisional power among the team members, and the degree of information acquisition on their quality. The suggested approach is applied in the special context of pairwise organizational choice for evaluating the performance of a class of decision rules, the value of participation in organizational decision making, the value of information on the quality of the available decision makers, and the efficiency loss associated with common restrictions on the design of the corporate's structure of decision making.     

A uniqueness result for extending orders; with application to collective choice as inconsistency resolution

Two axioms about extending a weak ordering of a set Ω to its power set 2^Ω uniquely determine a lexicographic weak ordering of 2^Ω. The solution is applied to collective choice to resolve majority cycle inconsistencies, and also contrasted with Condorcet.     

Shunning uncertainty: The neglect of learning opportunities

Financial, managerial, and medical decisions often involve alternatives whose possible outcomes have uncertain probabilities. In contrast to alternatives whose probabilities are known, these uncertain alternatives offer the benefits of learning. In repeat-choice situations, such learning brings value. If probabilities appear favorable (unfavorable), a choice can be repeated (avoided). In a series of experiments involving bets on the colors of poker chips drawn from bags, decision makers often prove to be blind to the learning opportunities offered by uncertain probabilities. They forgo significant expected payoffs when they shun uncertain alternatives in favor of known ones. Worse, when information is revealed, many make choices contrary to learning. Priming with optimal strategies offers little improvement. Such decision makers violate identified requirements for making rational decisions.     

Separating real incentives and accountability

Accountability—the expectation on the side of the decision maker that she may have to justify her decisions in front of somebody else—has been found by psychologists to strongly influence decision-making processes. The awareness of this issue remains however limited amongst economists, who tend to focus on the motivational effects of financial incentives. Accountability and incentives may provide different motivations for decision makers, and disentangling their effects is thus important for understanding real-world situations in which both are present. Separating accountability and incentives, I find different effects. Accountability is found to reduce preference reversals between frames, for which incentives have no effect. Incentives on the other hand are found to reduce risk seeking for losses, where accountability has no effect. In a choice task between simple and compound events, accountability increases the preference for the normatively superior simple event, while incentives have a weaker effect going in the opposite direction.     

Finite-dimensional utilities

Summary. Sufficient axioms are identified for the existence of a finite- dimensional quasilinear utility function whose lexicographically ordered vectors preserve a decision maker's preference order on a mixture set . It is shown that those axioms are also necessary for the linear lexicographic representation when the underlying set is a mixture space. Received: August 20, 1998; revised version: December 14, 1998     

Lexicographic compositions of multiple criteria for decision making

This paper considers two distinct procedures to lexicographically compose multiple criteria for social or individual decision making. The first procedure composes M binary relations into one, and then selects its maximal elements. The second procedure first selects the set of maximal elements of the first binary relation, and then within that set, chooses the maximal elements of the second binary relation, and iterates the procedure until the Mth binary relation. We show several distinct sets of conditions for the choice functions representing these two procedures to satisfy non-emptiness and choice-consistency conditions such as contraction consistency and path independence. We also examine the relationships between the outcomes of the two procedures. Finally we investigate under what conditions the outcomes of each procedure are independent of the order of lexicographic application of the criteria.