ExCEN Working Papers

Does playing a game in class improve students' ability to analyze the game using game theory? We report results from an experimental design which allows us to test a series of related hypotheses. We fail to find support for the conjectured learning-enhancing effects and discuss what lessons can be learned substantially and methodologically.

We use an experimental method to investigate whether systematic relationships exist across distinct aspects of individual preferences: risk aversion in monetary outcomes, altruism in a twoperson context, and social preferences in a larger group context. Individual preferences across these three contexts are measured, and there is no possibility for risk sharing, wealth effects, or updating expectations of the population choices. We find that social preferences are related to demographic variables, including years of education, gender, and age. Perhaps most importantly, self allocation in a two-person dictator game is related to social preferences in a group context. Participants who are more generous in a dictator game are more likely to vote against their selfinterest in a group decision-making task which we interpret to be expressions of social preferences.

Weber, Shafir, and Blais (2004) advocate use of the coefficient of variation (CV) as a measure of risk sensitivity and apply CV in a meta-analysis of data for risky choices by humans and animals. We critically re-examine the CV measure as either a normative or descriptive criterion for decision under risk. CV fails as a normative criterion because it violates first order stochastic dominance. Whether or not CV succeeds as a descriptive criterion depends on its consistency or inconsistency with data from experiments designed to test its distinctive properties. We report an experiment with human subjects motivated by salient monetary payoffs. The data are inconsistent with the hypothesis that the CVs of risky lotteries are a significant determinant of subjects’ choices between the lotteries and certain payoffs.

We consider two mechanisms to procure differentiated goods: a request for quote and an English auction with bidding credits. In the request for quote, each seller submits a price and the inherent quality of his good. Then the buyer selects the seller who offers the greatest difference in quality and price. In the English auction with bidding credits, the buyer assigns a bidding credit to each seller conditional upon the quality of the seller’s good. Then the sellers compete in an English auction with the winner receiving the auction price and his bidding credit. Game theoretic models predict the request for quote is socially efficient but the English auction with bidding credits is not. The optimal bidding credit assignment under compensates for quality advantages, creating a market distortion in which the buyer captures surplus at the expense of the seller’s profit and social efficiency. In experiments, the request for quote is less efficient than the English auctions with bidding credits. Moreover, both the buyer and seller receive more surplus in the English auction with bidding credits.

Expected value theory has been known for centuries to be subject to critique by St. Petersburg paradox arguments. And there is a traditional rebuttal of the critique that denies the empirical relevance of the paradox because of its apparent dependence on existence of credible offers to pay unbounded sums of money. Neither critique nor rebuttal focus on the question with empirical relevance: Do people make choices in finite St. Petersburg games that are consistent with expected value theory? This paper reports an experiment that addresses that question.

We propose a method for estimating subjective beliefs, viewed as a subjective probability distribution. The key insight is to characterize beliefs as a parameter to be estimated from observed choices in a well-defined experimental task, and to estimate that parameter as a random coefficient. The experimental task consists of a series of standard lottery choices in which the subject is assumed to use conventional risk attitudes to select one lottery or the other, and then a series of betting choices in which the subject is presented with a range of bookies offering odds on the outcome of some event that the subject has a belief over. Knowledge of the risk attitudes of subjects conditions the inferences about subjective beliefs. Maximum simulated likelihood methods are used to estimate a structural model in which subjects employ subjective beliefs to make bets. We present evidence that some subjective probabilities are indeed best characterized as probability distributions with non-zero variance.

Crime in the mail sector can hamper the development of electronic markets. We use a field experiment to detect crime and measure its differential impacts. We subtly, and realistically, manipulate the content and information available in mail sent to households and detect high levels of shirking and stealing. Eighteen percent of the mail never arrived at its destination, and even more was lost if there was even a slight hint of something additional inside the envelope. Our study demonstrates that privatization has been unable to extricate moral hazard and that crime is strategic and not equally distributed across the population.

We study the risk attitudes of an important segment of the economy: managers. We conduct artefactual field experiments with 130 managers from 12 industrial companies. Our analysis is particularly careful to evaluate alternative models of decision-making under risk. In general, we find that the managers in our sample are moderately risk averse. Assuming a standard EUT model they exhibit similar risk attitudes as other sample populations. However, we find some differences within our sample. Superiors exhibit a higher level of risk aversion than team members that work for them in their department. Comparing purchasing managers with a random sample of non-purchasing managers from different corporate functions such as controlling, sales, engineering and so on, we cannot conclude that they differ from each other. We show that alternative theories of risky behavior provide complementary information on the risk attitude of industrial managers. While an expected utility theory model only characterizes managers as globally risk averse, we learn from a prospect theory model that the managers in our sample are only risk averse for a certain range of payoffs. For other payoffs, they even exhibit risk-seeking behavior. The reference point that determines which outcomes are to be viewed as losses and which as gains is not that induced by the task frame. We show that subjects had implicit expectations about their earning in the experiment, and used these expectations to evaluate the lotteries presented to them. Remarkably, the managers in our sample did not weigh probabilities and they did not exhibit a hypothetical bias in their decisions.

We critically review the methodological practices of two research programs which are jointly called ‘neuroeconomics’. We defend the first of these, termed ‘neurocellular economics’ (NE) by Ross (2008), from an attack on its relevance by Gul and Pesendorfer (2008) (GP). This attack arbitrarily singles out some but not all processing variables as unimportant to economics, is insensitive to the realities of empirical theory testing, and ignores the central importance to economics of ‘ecological rationality’ (Smith 2007). GP ironically share this last attitude with advocates of ‘behavioral economics in the scanner’ (BES), the other, and better known, branch of neuroeconomics. We consider grounds for skepticism about the accomplishments of this research program to date, based on its methodological individualism, its ad hoc econometrics, its tolerance for invalid reverse inference, and its inattention to the difficulties involved in extracting temporally lagged data if people’s anticipation of reward causes pre-emptive blood flow.

Literature exploring other-regarding behavior reveals interesting phenomena, yet less attention has been given to implications for foundational assumptions within economics. Our study synthesizes the evidence, explaining why recent work challenges rational choice theory as well as its special case, convex preference theory. Guided by this understanding, we advance a theory of choice that exhibits monotonicity with respect to observable reference points. This modification of choice theory establishes consistency with otherwise-anomalous data. We explain how our theory organizes extant data and has applications to strategic games with contractions. We report an experiment designed to test central features of the new theory.

Subjective probabilities play a role in many economic decisions. There is a large theoretical literature on the elicitation of subjective probabilities, and an equally large empirical literature. However, there is a gulf between the two. The theoretical literature proposes a range of procedures that can be used to recover subjective probabilities, but stresses the need to make strong auxiliary assumptions or “calibrating adjustments” to elicited reports in order to recover the latent probability. With some notable exceptions, the empirical literature seems intent on either making those strong assumptions or ignoring the need for calibration. We illustrate how the joint estimation of risk attitudes and subjective probabilities using structural maximum likelihood methods can provide the calibration adjustments that theory calls for. This allows the observer to make inferences about the latent subjective probability, calibrating for virtually any well-specified model of choice under uncertainty. We demonstrate our procedures with experiments in which we elicit subjective probabilities. We calibrate the estimates of subjective beliefs assuming that choices are made consistently with expected utility theory or rank-dependent utility theory. Inferred subjective probabilities are significantly different when calibrated according to either theory, thus showing the importance of undertaking such exercises. Our findings also have implications for the interpretation of probabilities inferred from prediction markets.

Theories of decision under risk that assume decreasing marginal utility of money have been critiqued with concavity calibration arguments. Since that critique uses varying payoffs and fixed probabilities, it cannot have implications for calibration of nonlinear probability transformation, which is another way to model risk aversion. The concavity calibration critique also has no implication for theories with variable reference points. This paper introduces a new type of (varying-probabilities, fixed-payoffs) calibration that applies to nonlinear transformation of probabilities. It also applies to theories with constant or variable reference points. The two types of calibrations yield dual paradoxes: a pattern of risk aversion that conforms to the (resp. dual) independence axiom implies implausible risk aversion for theories with functionals that are linear in payoffs (resp. probabilities). Functionals that are nonlinear in both payoffs and probabilities are subject to both types of calibration critique. The dual calibrations make clear why plausibility problems with theories of decision under risk may be fundamental. They are fundamental if their empirical relevance can be demonstrated. This paper reports seven experiments that provide data on the empirical relevance of the dual calibration critique of decision theory.

Experiments are conducted with various purposes in mind including theory testing, mechanism design and measurement of individual characteristics. In each case a careful researcher is constrained in the experimental design by prior considerations imposed either by theory, common sense or past results. We argue that the integration of the design with these elements needs to be taken even further. We view all these elements that make up the body of research methodology in experimental economics as mutually dependant and therefore take a systematic approach to the design of our experimental research program. Rather than drawing inferences from individual experiments or theories as if they were independent constructs, and then using the findings from one to attack the other, we recognize the need to constrain the inferences from one by the inferences from the other. Any data generated by an experiment needs to be interpreted jointly with considerations from theory, common sense, complementary data, econometric methods and expected applications. We illustrate this systematic approach by reference to a research program centered on large artefactual field experiments we have conducted in Denmark. An important contribution that grew out of our work is the complementarity between lab and field experiments.

Is mutually beneficial cooperation in trust games more prevalent with private property or common property? Does the strength of property right entitlement affect the answer? Cox, Ostrom, Walker, et al. [1] report little difference between cooperation in private and common property trust games. We assign stronger property right entitlements by requiring subjects to meet a performance quota in a real effort task to earn their endowments. We find that cooperation is lower in common property trust games than in private property trust games, which is an idiosyncratic prediction of revealed altruism theory [2].

We show that observed choices in discounting experiments are consistent with roughly one-half of the subjects using exponential discounting and one-half using quasi-hyperbolic discounting. We characterize the latent data generating process using a mixture model which allows different subjects to behave consistently with each model. Our results have substantive implications for the assumptions made about discounting behavior, and also have significant methodological implications for the manner in which we evaluate alternative models when there may be complementary data generating processes.

This short paper investigates the consequences of voters identifying with special interest groups in a spatial model of electoral competition. We show that, by effectively coordinating voting behavior, identification with interest groups leads to an increase in the size of the winning set, that is, the set of policy platforms for the challenger that will defeat the incumbent. Consequently, our paper points at a novel process through which interest groups can enhance the electoral chances of a challenger.