Demystifying the 'Metric Approach to Social Compromise with the Unanimity Criterion'

In a recent book and earlier studies, Donald Saari well clarifies the source of three classical impossibility theorems in social choice and proposes possible escape out of these negative results. The objective of this note is to illustrate the relevance of these explanations in justifying the metric approach to the social compromise with the unanimity criterion.social choice, impossibility theorems, metric approach to compromise with the unanimity criterion

Price Setting and Price Adjustment in Some European Union Countries: Introduction to the Special Issue

This introductory essay briefly summarizes the eleven empirical studies of price setting and price adjustment that are included in this special issue. The studies, which use data from several European countries, were conducted as part of the European Central Bank’s Inflation Persistence Network.Price Rigidity, Price Flexibility, Cost of Price Adjustment, Menu Cost, Managerial and Customer Cost of Price Adjustment, Pricing, Price System, Price Setting, New Keynesian Economics, Store-Level Data, Micro-Level Data, Product-Level Data

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-maker's capabilities and the selection of the appropriate aggregation rule. The major and so far unresolved difficulty is the former necessity. This paper 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-maker's 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 celebrated theorem and its extensions, such as sufficiently high decision-making quality, skill homogeneity or existence of a sufficiently large group of decision makers.

Shorting the Bear: A Test of Anecdotal Evidence of Insider Trading in Early Stages of the Sub-Prime Market Crisis

This article uses trading data in the options market for shares in The Bear Sterns Companies (BSC) during the early stages of the US sub-prime crisis as a laboratory to examine the incidence of insider trading. We take the perspective of a regulator making use of hindsight to identify the most propitious periods for insider trades and to identify market activity indicative of insiders. Half the value of options traded were on 19 percent of the days, mostly in contracts in or close-to the money and near to expiry. We find persuasive evidence that insiders could have been active in trading Bear Sterns stock during this period.insider trading, forensic finance, Bear Sterns

Attitudes to Risk and Roulette

We present an empirical framework for determining whether or not customers at the roulette wheel are risk averse or risk loving. Thus, we present a summary of the Aumann-Serrano (2007) risk index as generalized to allow for the presence of risk lovers by Schnytzer and Westreich (2010). We show that, for any gamble, whereas riskiness increases for gambles with positive expected return as the amount placed on a given gamble is increased, the opposite is the case for gambles with negative expected return. Since roulette involves binary gambles, we restrict our attention to such gambles exclusively and derive empirically testable hypotheses. In particular, we show that, all other things being equal, for gambles with a negative expected return, riskiness decreases as the size of the contingent payout increases. On the other hand, riskiness increases if the gamble has a positive expected return. We also prove that, for positive return gambles, riskiness increases, ceteris paribus, in the variance of the gamble while the reverse is true for gambles with negative expected returns. Finally, we apply these results to the specific gambles involved in American roulette and discuss how we might distinguish between casino visitors who are risk averse and those who are risk loving as well as those who may suffer from gambling addictions of one form or another.

A Field Study of Social Learning

We present a field study of social learning. The setting is a pair of adjacent fast food restaurants serving very similar cuisine whose main clientele are the students at a nearby major university. We observed whether an uninformed customer's choice of restaurant depends on the relative queue lengths at the two restaurants. Observations were made at two separate observation periods, the start of the academic year, when a significant proportion of customers had little or no experience with either restaurant, and the middle of the year, when most customers already had previous experience with the restaurants. It is found, consistent with the social learning hypothesis, that relative queue length has a significant effect at the first period but not at the second.

Interactions Between Local and Migrant Workers at the Workplace

In this paper we consider the interaction between local workers and migrants in the production process of a firm. Both local workers and migrants can invest effort in assimilation activities in order to increase the assimilation of the migrants into the firm and so by increase their interaction and production activities. We consider the effect, the relative size (in the firm) of each group and the cost of activities, has on the assimilation process of the migrants.Assimilation; Contracts; Ethnicity; Market Structure; Networks; Harassment

Business as Usual: A Consumer Search Theory of Sticky Prices and Asymmetric Price Adjustment

Empirical evidence suggests that prices are sticky with respect to cost changes. Moreover, prices respond more rapidly to cost increases than to cost decreases. We develop a search theoretic model which is consistent with this evidence and allows for additional testable predictions. Our results are based on the assumption that buyers do not observe the sellers costs, but know that cost changes are positively correlated across sellers. In equilibrium, a change in price is likely to induce consumer search, which explains sticky prices. Moreover, the signal conveyed by a price decrease is different from the signal conveyed by a price increase, which explains asymmetry in price adjustment.

False Consciousness in Financial Markets: Or is it in Ivory Towers?

In general, models in finance assume that investors are risk averse. An example of such a recent model is the pioneering work of Aumann and Serrano, which presents an economic index of riskiness of gambles which is independent of wealth and holds (as might be understood from the adjective “economic”) for exclusively risk averse investors. In their paper, they discuss gambles with positive expected returns which will be accepted or rejected by agents which different levels of risk aversion. The question never asked by the authors (and in most of the finance literature) is: Who is offering these attractive gambles? To arrive at an answer, we extend the Aumann-Serrano risk index in such a way that it accommodates gambles with either positive or negative expectations and is thus suitable for both the risk averse and risk lovers. Once we allow for the existence of risk lovers, it may be shown that in financial markets, many gambles with negative expectations are taken either knowingly or unknowingly so that there are always people that act as if they are risk lovers. The paper concludes with a brief discussion of the implications of our result, in particular that gambling is by no means restricted to the casino or the track.