Persuasion,binary choice,and the costs of dishonesty

We study the strategic interaction between a decision maker who needs to take a binary decision but is uncertain about relevant facts and an informed expert who can send a message to the decision maker but has a preference over the decision. We show that the probability that the expert can persuade the decision maker to take the expert’s preferred decision is a hump-shaped function of his costs of sending dishonest messages.     

Inter-temporal choices with temporal reference dependence

I develop an intertemporal choice model for rational deviators whose preferences depend not only on their actual consumption but also on comparison to their beliefs about the optimal consumption. The standard decision maker is loss averse with respect to this belief-dependent reference point. When psychologically weighted loss aversion is low, a decision maker deviates from the standard intertemporal choice behavior and over-consumption, as well as the alternative possibility of under-consumption can be rationalized. When the decision maker has time-varying degrees of loss aversion, he re-optimizes the consumption plan through adjusted beliefs as subsequent selves realize that past decision for the present period is no longer optimal. In the dynamic model, I solve for consistent intertemporal optimization rules by which a dynamic deviator should meet rational intertemporal consistency at each point in time. Finally, I demonstrate that the dynamic reference dependent model can solve a puzzling feature in lifecycle consumption data.     

When mandatory disclosure hurts: Expert advice and conflicting interests

We study the quality of advice that an informed and biased expert gives to an uninformed decision maker. We compare two scenarios: mandatory disclosure of the bias and nondisclosure, where information about the bias can only be revealed through cheap-talk. We find that in many scenarios nondisclosure allows for higher welfare for both parties. Hiding the bias allows for more precise communication for the more biased type and, if different types are biased in different directions, may allow for the same for the less biased type. We identify contexts where equilibrium revelation allows but mandatory disclosure prevents meaningful communication.     

Aggregation of multiple prior opinions

Experts are asked to provide their advice in a situation of uncertainty. They adopt the decision maker?s utility function, but each has a potentially different set of prior probabilities, and so does the decision maker. The decision maker and the experts maximize the minimal expected utility with respect to their sets of priors. We show that a natural Pareto condition is equivalent to the existence of a set Λ of probability vectors over the experts, interpreted as possible allocations of weights to the experts, such that (i) the decision maker?s set of priors is precisely all the weighted-averages of priors, where an expert?s prior is taken from her set and the weight vector is taken from Λ; (ii) the decision maker?s valuation of an act is the minimal weighted valuation, over all weight vectors in Λ, of the experts? valuations.     

Debates and Decisions: On a Rationale of Argumentation Rules

We view a debate as a mechanism by which an uninformed decision maker (the listener) extracts information from two informed debaters, who hold contradicting positions regarding the right decision. During the debate, the debaters raise arguments and, based on these arguments, the listener reaches a conclusion. Using a simple example, we investigate the mechanism design problem of constructing rules of debate that maximize the probability that the listener reaches the right conclusion, subject to constraints on the form and length of the debate. It is shown that optimal debate rules have the property that the conclusion drawn by the listener is not necessarily the same as the conclusion he would have drawn, had he interpreted the information, revealed to him or her during the debate, literally. The optimal design of debate rules requires that the information elicited from a counterargument depends on the argument it counterargues. We also link our discussion with the pragmatics literature. Journal of Economic Literature Classification Numbers: C72, D78.     

PARTISAN ADVOCATES

This paper studies the problem of an uninformed decision maker who acquires expert advice prior to making a decision. I show that it is less costly to hire partisan agents than impartial agents, especially under advocacy, and that the decision maker prefers partisan advocacy to other forms of institutions. I also extend the literature, originating with Dewatripont and Tirole ( 1999 ), to a setting with contracts that condition on information provided and not just the decision made.     

Multiple Criteria Decision Making: A Case Study of the Columbia River Salmon Recovery Plan

A common problem faced by decision makers is choosing the best alternative from among many. Traditionally, such decisions in the public arena were made using benefit-cost analysis, which involves the conversion of all costs and benefits associated with a project into monetary terms. But public projects often have a variety of economic, ecological, social and political objectives, many of which cannot or perhaps should not be converted to monetary terms. In such projects decisions must be made based on multiple, even conflicting objectives. Multiple criteria decision making (MCDM) methods are widely used for such decisions. However, a common disadvantage among many such methods available in the literature is that they require input from a real decision maker. This paper presents the development and application of an expert system based on fuzzy set theory and IF-THEN rules. The system mimics a real decision maker. Along with two conventional MCDM methods the developed expert system was applied on a data set from the Columbia River Basin salmon recovery plan to assess its potential usefulness as a decision-making tool for natural resource projects. The results suggest that the fuzzy expert system is easy to develop and makes better decisions than the other two conventional MCDM methods used.     

Recursive robust estimation and control without commitment

In a Markov decision problem with hidden state variables, a posterior distribution serves as a state variable and Bayes’ law under an approximating model gives its law of motion. A decision maker expresses fear that his model is misspecified by surrounding it with a set of alternatives that are nearby when measured by their expected log likelihood ratios (entropies). Martingales represent alternative models. A decision maker constructs a sequence of robust decision rules by pretending that a sequence of minimizing players choose increments to martingales and distortions to the prior over the hidden state. A risk sensitivity operator induces robustness to perturbations of the approximating model conditioned on the hidden state. Another risk sensitivity operator induces robustness to the prior distribution over the hidden state. We use these operators to extend the approach of Hansen and Sargent [Discounted linear exponential quadratic Gaussian control, IEEE Trans. Automat. Control 40(5) (1995) 968-971] to problems that contain hidden states.     

Choosing the two finalists

This paper studies a decision maker who for each choice set selects a subset of (at most) two alternatives. We axiomatize three types of procedures: (i) The top two: the decision maker has in mind an ordering and chooses the two maximal alternatives. (ii) The two extremes: the decision maker has in mind an ordering and chooses the maximal and the minimal alternatives. (iii) The top and the top: the decision maker has in mind two orderings and he chooses the maximal element from each.     

Comparative cheap talk

When are comparative statements credible? We show that simple complementarity conditions ensure that an expert with private information about multiple issues can credibly rank the issues for a decision maker. By restricting the expert's ability to exaggerate, multidimensional cheap talk of this form permits communication when it would not be credible in a single dimension. The communication gains can be substantial with even a couple of dimensions, and the complete ranking is asymptotically equivalent to full revelation as the number of issues becomes large. Nevertheless, partial rankings are sometimes more credible and/or more profitable for the expert than the complete ranking. Comparative cheap talk is robust to asymmetries that are not too large. Consequently, for sufficiently many independent issues, there are always some issues sufficiently symmetric to permit comparative cheap talk.     

The Case For Strategic Realism: A Response To Lawson

Tony Lawson makes a compelling case that it is only naive realism that feminist social scientists and philosophers need to avoid, not any and all realist arguments. However, he leaves mysterious, on the one hand, why so many feminists have preferred epistemological to ontological arguments and, on the other hand, why naive realism, which is indeed problematic, can appear to be a good scientific/epistemic strategy. The essay below tries to demystify these phenomena, notes a possible misleading aspect of his use of the term "epistemological relativism", and argues for a somewhat more limited value of the ontological argument he proposes for standpoint epistemologies.     

Optimal agenda-setter timing

Abstract .  We analyze the optimal timing problem of an agenda setter who can propose a project that is then voted on by a committee. The payoff consists of a common stochastic component and an idiosyncratic component that differs among committee members. The agenda setter may be biased for or against the project, relative to the median committee member, and chooses when to call the vote. We analyze how the timing decision depends on the political environment and the bias of the agenda setter. We show that both positively and negatively biased agenda setters can implement decisions that differ from those preferred by the median committee member.     

Information transmission when the sender''s preferences are uncertain

In deciding on the magnitude of a certain action (say, investment), a decision maker relies on the report of an informed and interested expert who can suppress favorable information. The main departure from the related literature is that the decision maker is uncertain as to whether the expert is of a type that wants to minimize the magnitude of the action or to maximize it. The unique equilibrium outcome is fully characterized by a threshold level of favorable information. If the information is more favorable than that threshold level and if the expert is of the type that wants to maximize the magnitude of the action, the information is fully revealed. In all other cases, the expert report less favorable information and the equilibrium inference is that, in expectation, the actual information is just as favorable as the threshold level.     

The art of conversation: eliciting information from experts through multi-stage communication

We examine the strategic interaction between an informed expert and an uninformed decision maker, extending the analysis of Crawford and Sobel (Econometrica 50 (1982) 1431). We modify their model to allow for more extensive communication between the two parties and show that face-to-face communication between the expert and the uninformed decision maker followed by a written report from the expert leads to improved information transmission. In (almost) all cases, there exists an equilibrium in our modified model that ex ante Pareto dominates all of the equilibria identified by Crawford and Sobel. This remains true even if the expert's bias is so great that in their model no information would be disclosed.     

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.     

The rationality and efficacy of decisions under uncertainty and the value of an experiment

Summary A decision maker faces a known prior distribution over payoff relevant states. We compare the expected utility of this individual under two scenarios. In the first, the decision maker makes a choice without further information. In the second, the decision maker has access to an experiment before choosing an action. However, the decision maker does not know the true joint distribution over states and messages. The value of the experiment as measured by the difference in the two utility levels can be negative as well as positive. We give a condition which is necessary and sufficient for the experiment to be valuable in our sense, for any decision problem.An earlier version of this paper was circulated under the title Noisy Bayes Updating and the Value of Information. We have gained from the comments of Stephen Coate, John Geanakoplos, Larry Samuelson, Timothy Van Zandt and seminar participants at Harvard Business School, Princeton, Boston University, the international conference on game theory at Stony Brook 1992 and the Winter meeting of the Econometric Society at Anaheim 1993. The first author received support for this project from NSF grant #SES-9308515 and a University of Pennsylvania Research Foundation Grant.     

Preference for Flexibility and Dynamic Consistency

Dekel, Lipman, and Rustichini [3] characterize preferences over menus of lotteries that can be represented by the use of a unique subjective state space and a prior. We investigate what would be the appropriate version of Dynamic Consistency in such a setup. The condition we find, which we call Flexibility Consistency, is linked to a comparative theory of preference for flexibility. When the subjective state space is finite, we show that Flexibility Consistency is equivalent to a subjective version of Dynamic Consistency and that it implies that the decision maker is a subjective state space Bayesian updater. Later we characterize when a collection of signals can be interpreted as a partition of the subjective state space of the decision maker.     

Robust estimation and control under commitment

In a Markov decision problem with hidden state variables, a decision maker expresses fear that his model is misspecified by surrounding it with a set of alternatives that are nearby as measured by their expected log likelihood ratios (entropies). Sets of martingales represent alternative models. Within a two-player zero-sum game under commitment, a minimizing player chooses a martingale at time 0. Probability distributions that solve distorted filtering problems serve as state variables, much like the posterior in problems without concerns about misspecification. We state conditions under which an equilibrium of the zero-sum game with commitment has a recursive representation that can be cast in terms of two risk-sensitivity operators. We apply our results to a linear quadratic example that makes contact with findings of T. Ba?ar and P. Bernhard [H^∞-Optimal Control and Related Minimax Design Problems, second ed., Birkhauser, Basel, 1995] and P. Whittle [Risk-sensitive Optimal Control, Wiley, New York, 1990].     

A Bayesian Approach to Uncertainty Aversion

The Ellsberg paradox demonstrates that people's beliefs over uncertain events might not be representable by subjective probability. We show that if a risk averse decision maker, who has a well defined Bayesian prior, perceives an Ellsberg type decision problem as possibly composed of a bundle of several positively correlated problems, she will be uncertainty averse. We generalize this argument and derive sufficient conditions for uncertainty aversion.     

Regret aversion and opportunity dependence

This paper provides an axiomatic model of decision making under uncertainty in which the decision maker is driven by anticipated ex post regrets. Our model allows both regret aversion and likelihood judgement over states to coexist. Also, we characterize two special cases, minimax regret with multiple priors that generalizes Savage's minimax regret, and a smooth model of regret aversion.