Publications

2004
D. Granot, H. Hamers, J. K., & Maschler, M. . (2004). Chinese Postman Games on a Class of Eulerian Graphs. Discussion Papers. presented at the 7. Retrieved from /files/dp366.pdf Publisher's VersionAbstract
The extended Chinese postman (CP) enterprize is induced by a connected and undirected graph G. A server is located at some fixed vertex of G, to be referred to as the post office. Each player resides in a single edge, and each edge contains at most one player. Thus, some of the edges can be public . Each edge has a cost and a prize attached to it. The players need some service, e.g., mail delivery, which requires the server to travel from the post office and visit all edges wherein players reside, before returning to the post office. The server collects the prize attached to an edge upon the first traversal of this edge, but the cost of an edge is incurred every time it is traversed. The cost of a cheapest tour for each coalition defines a CP cost game. The issue is how to allocate, among the players, the cost that the server incurs. We study the class of extended CP enterprizes which are induced by Eulerian graphs satisfying two properties: The 4-cut property (Definition 4.4) and completeness (Definition 4.8). For this class we prove that the core, resp., the nucleolus when the core is not empty, are Cartesian products of the cores, resp., nucleoli of CP enterprizes whose graphs are simple cycles generated from G by identifying therein the end points of each elementary path (Definition 4.3). Finally, for the class of extended complete Eulerian graphs having the 4-cut property, we are able to test core membership in O(n) time, and when the core is not empty, we show how to calculate the nucleolus in O(n^2) time, n being the number of players.
Zvika Neeman, M. D. P., & Simhon, A. . (2004). Corruption and Openness. Discussion Papers. presented at the 3. Retrieved from /files/dp353.pdf Publisher's VersionAbstract
We report an intriguing empirical observation. The relationship between corruption and output depends on the economy's degree of openness: in open economies, corruption and GNP per capita are strongly negatively correlated; but in closed economies, there is no relationship at all. This stylized fact is robust to a variety of different empirical specifications. In particular, the same basic pattern persists if we use alternative measures of openness, if we focus on different time periods, if we restrict the sample to include only highly corrupt countries, if we restrict attention to specific geographic areas or to poor countries, and if we allow for the possible endogeneity of both the corruption and openness measures. We find that the extent to which corruption affects output is determined primarily by the degree of financial openness. The difference between closed and open economies is mainly due to the different effect of corruption on capital accumulation. We present a model, consistent with these findings, in which the main channel through which corruption affects output is capital drain.
Kareev, K. F., & Yaakov, . (2004). Does Decision Quality (Always) Increase with the Size of Information Samples? Some Vicissitudes in Applying the Law of Large Numbers. Discussion Papers. presented at the 1, Journal of Experimental Psychology: Learning, Memory and Cognition 32 (2006), 883-903. Retrieved from /files/dp347.pdf Publisher's VersionAbstract
Adaptive decision-making requires that environmental contingencies between decision options and their relative advantages and disadvantages be assessed accurately and quickly. The research presented in this article addresses the challenging notion that contingencies may be more visible from small than large samples of observations. An algorithmic account for such a ""less-is-more"" effect is offered within a threshold-based decision framework. Accordingly, a choice between a pair of options is only made when the contingency in the sample that describes the relative utility of the two options exceeds a critical threshold. Small samples - due to their instability and the high dispersion of their sampling distribution - facilitate the generation of above-threshold contingencies. Across a broad range of parameter values, the resulting small-sample advantage in terms of hits is stronger than their disadvantage in terms of false alarms. Computer simulations and experimental findings support the predictions derived from the threshold model. In general, the relative advantage of small samples is most apparent when information loss is low, when decision thresholds are high, and when ecological contingencies are weak to moderate.
Cohen, D. . (2004). Evolutionary Ecology of Species Diversity in Stressed and Extreme Environments, The. Discussion Papers. presented at the 3. Retrieved from /files/dp352.pdf Publisher's Version
Aumann, R. J., & Furstenberg, H. . (2004). Findings of the Committee to Investigate the Gans-Inbal Results on Equidistant Letter Sequences in Genesis. Discussion Papers. presented at the 6. Retrieved from /files/dp364.1.pdf Publisher's VersionAbstract
In 1996, a committee was formed to examine the results that had been reported by H.J. Gans regarding the existence of "encoded" text in the bible foretelling events that took place many years after the Bible was written. The committee performed two additional tests in the spirit of the Gans experiments. Both tests failed to confirmed the existence of the putative code.
Larry Goldstein, Y. R. . (2004). Functional BRK Inequalities, and Their Duals, with Applications. Discussion Papers. presented at the 11, Journal of Theoretical Probability 20, 275-293 (2007). Retrieved from /files/ Revision of September 12 2015.pdf, dp374.pdf Publisher's VersionAbstract
The inequality conjectured by van den Berg and Kesten in [9], and proved by Reimerin [6], states that for A and B events on S, a product of finitely many finite sets, and P any product measure on S, P(A¿B) P(A)P(B), where A¿B are the elementary events which lie in both A and B for `disjoint reasons.' This inequality on events is the special case, for indicator functions, of the inequalityhaving the following formulation. Let X be a random vector with n independent components, each in some space Si (such as„d), and set S = ˆni=1Si. Say that the function f : S †’„depends on K Š‚ 1,...,n if f(x) = f(y) whenever xi = yi for all i ˆˆ K. Then for any given finite or countable collections of non-negative real valued functions f$\pm$$\pm$ˆˆA, g²²ˆˆB on S which depend on K$\pm$ and L² respectively,EsupK$\pm$ˆ\copyrightL²=ˆłdots} f$\pm$(X) g²(X) Esup f$\pm$(X) Esup g²(X). Related formulations, and functional versions of the dual inequality on events by Kahn,Saks, and Smyth [4], are also considered. Applications include order statistics, assignment problems, and paths in random graphs.
Neeman, O. M., & Zvika, . (2004). Inspection in Markets for Experience Goods. Discussion Papers. presented at the 2. Retrieved from /files/db349.pdf Publisher's VersionAbstract
We consider a simple dynamic "collective reputation" model of a market for an experience good into''  which we introduce imperfect quality inspections. In each period two markets operate: a prime market''  for sellers with a good reputation, and a regular market for all other sellers. In every period, the quality of produced goods is inspected, and producers who have been found to produce low quality goods are barred from selling in the prime market in the next period. We demonstrate that the average quality of the good in both markets may decrease as inspection technology improves. A few applications of the model are discussed.
Bar-Hillel, A. M., & Maya, . (2004). Loss Aversion and Status-Quo Label Bias. Discussion Papers. presented at the 11, Social Cognition, 2010, Vol. 28, No. 2, Pp. 192-206. Retrieved from /files/ SQLB-373.pdf Publisher's VersionAbstract
It has been noted and demonstrated that people are reluctant to make changes in their current state (called the status quo bias, Samuelson & Zeckhauser, 1988), and to trade objects they own (called the endowment effect, Thaler, 1980). This reluctance has been explained by a combination of loss aversion and reference dependence which causes the status quo to appear better than its alternative, ceteris paribus. In the present study, respondents were asked to rate the attractiveness of various policies, and to list their pros and cons. We find that just labeling some state of affairs status quo enhances its rating (which we call the status quo label bias); namely, a policy seemed more attractive to respondents who thought it is the status quo than to those who did not. An analysis of the listed pros and cons provides evidence that a model of the balance of a policy's pros and cons is a good predictor of that policy's attractiveness. Rendering the pros and cons in terms of losses and gains provides evidence that losses do, indeed, loom larger than gains. When put together, our results provide an empirical grounding for the loss aversion explanation of the status quo bias.
David Assaf, L. G., & Samuel-Cahn, E. . (2004). Maximizing Expected Value with Two Stage Stopping Rules. Discussion Papers. presented at the 3, Random Walks, Sequential Analysis and Related Topics, Chao Agnes Hsiung, Zhiliang Ying and Cun-Hui Zhang, Eds. World Scientific, Singapore (2006), 3-27. Retrieved from /files/db351.pdf Publisher's VersionAbstract
Let Xn, ¦,X1 be i.i.d. random variables with distribution function F and finite expectation. A statistician, knowing F, observes the X values sequentially and is given two chances to choose X's using stopping rules. The statistician's goal is to select a value of X as large as possible. Let Vn2 equal the expectation of the larger of the two values chosen by the statistician when proceeding optimally. We obtain the asymptotic behavior of the sequence Vn2 for a large class of F's belonging to the domain of attraction (for the maximum) D(GII''$\pm$), where GII''$\pm$ (x) = exp(-x-''$\pm$)''(x > 0) with$\pm$ > 1. The results are compared with those for the asymptotic behavior of the classical one choice value sequence Vn1, as well as with the ""prophet value"" sequence E(maxXn, ¦,X1), and indicate that substantial improvement is obtained when given two chances to stop, rather than one.
Judith Avrahami, T. A., & Weiss-Chasum, D. . (2004). Mysteries of the Diagonal: Gender-Related Perceptual Asymmetries, The. Discussion Papers. presented at the 2, Perception & Psychophysics (In Press). Retrieved from /files/db348.pdf Publisher's VersionAbstract
The paper reports a perceptual asymmetry for the two diagonals that is related to gender such that females prefer the diagonal spanning from top-right to bottom left (/) while males the opposite one (''). This relationship is observed in a variety of tasks: Aesthetic judgment of paintings, spotting differences between two paintings, and visual search for a tilted line among similarly tilted distractors. The paper does not provide an explanation of the relationship between this asymmetry and gender but rules out several potential mediating factors, such as eye dominance, head tilt, handedness, and hemispheric differences. At the same time, the paper does outline the scope of the phenomenon: The asymmetry is found both for meaningful and for meaningless stimuli and both at brief and at extended presentation. Moreover, the asymmetry is found related to the tilt of the visual elements that require processing not to their location in the visual field.
Neeman, A. H., & Zvika, . (2004). On the Generic (Im)possibility of Full Surplus Extraction in Mechanism Design. Discussion Papers. presented at the 2, Econometrica 74 (2006), 213-233. Retrieved from /files/dp350.pdf Publisher's VersionAbstract
A number of studies, most notably Cr×mer and McLean (1985, 1988), have shown that in Harsanyi type spaces of a fixed finite size, it is generically possible to design mechanisms that extract all the surplus  from players, and as a consequence, implement any outcome as if the players' private information  were commonly known. In contrast, we show that within the set of common priors on the universal type  space, the subset of priors that permit the extraction of the players' full surplus is shy. Shyness is a  notion of smallness for convex subsets of infinite-dimensional topological vector spaces (in our case,  the set of common priors), which generalizes the usual notion of zero Lebesgue measure in  finite-dimensional spaces.
Sudholter, B. P., & Peter, . (2004). On the Non-Emptiness of the Mas-Colell Bargaining Set. Discussion Papers. presented at the 5, Journal of Mathematical Economics 41 (2005), 1060-1068. Retrieved from /files/dp360.pdf Publisher's VersionAbstract
We introduce an extension of the Mas-Colell bargaining set and construct, by an elabo- ration on a voting paradox, a superadditive four-person nontransferable utility game whose extended bargaining set is empty. It is shown that this extension constitutes an upper hemi- continuous correspondence. We conclude that the Mas-Colell bargaining set of a non-levelled superadditive NTU game may be empty.
Samuel-Cahn, L. G., & Ester, . (2004). Optimal Two Choice Stopping on an Exponential Sequence. Discussion Papers. presented at the 11, Sequential Analysis 25 (2006), 351-363. Retrieved from /files/dp375.pdf Publisher's VersionAbstract
Asymptotic results for the problem of optimal two choice stopping on an n elementlong i.i.d. sequence Xn, . . . ,X1 have previously been obtained for two of the threedomains of attraction. An asymptotic result is proved for the exponential distribution,a representative from the remaining, Type I domain, and it is conjectured that thesame behavior obtains for all Type I distributions.
Olivier Gossner, P. H., & Neyman, A. . (2004). Optimal Use of Communication Resources. Discussion Papers. presented at the 12. Retrieved from /files/dp377.pdf Publisher's VersionAbstract
We study a repeated game with asymmetric information about a dynamic state of nature. In the course of the game, the better informed player can communicate some or all of his information with the other. Our model covers costly and/or bounded communication. We characterize the set of equilibrium payoffs, and contrast these with the communication equilibrium payoffs, which by definition entail no communication costs.
Yaari, W. G. ¼th, & E., M. . (2004). Parity, Sympathy, and Reciprocity. Discussion Papers. presented at the 3. Retrieved from /files/dp354.pdf Publisher's Version
Harel, E. G., & Alon, . (2004). Probability Matching and the Law: A Behavioral Challenge to Law & Economics. Discussion Papers. presented at the 7. Retrieved from /files/dp368.pdf Publisher's VersionAbstract
Contrary to the conventional assumption that individuals maximize payoffs, robust experimental studies show that individuals who face repeated choices involving probabilistic costs and benefits often make sub-optimal decisions by applying the strategy of "probability matching." The following study, by integrating this literature with the traditional models of law and economics, and through experimental illustration, presents the possible effects of probability matching in the legal context. The paper also explores how probability matching can guide policy making.
Maya Bar-Hillel, D. B., & Attali, Y. . (2004). Scoring and Keying Multiple Choice Tests: A Case Study in Irrationality. Discussion Papers. presented at the 9, Mind and Society 4 (2005), 3-12. Retrieved from /files/dp370.pdf Publisher's VersionAbstract
We offer a case-study in irrationality, showing that even in a high stakes, deliberate context, highly intelligent professionals may adopt dominated practices. Multiple-choice tests (MCTs) enjoy many advantages that made them popular tools in educational and psychological measurement. But they suffer from the so-called guessing problem: test-makers cannot distinguish lucky guesses from answers based on knowledge. One way professional test-makers have dealt with this problem is by attempting to lower the incentive to guess, through penalizing errors (called formula scoring). Another is to rid tests of various cues (e.g., a preponderance of correct answers in middle positions) that might help testwise test-takers guess at better than chance odds. Key balancing is the strategy test-takers adopted for ridding tests of positional biases. We show that formula scoring and key balancing, though widespread and intuitively appealing, are in fact "irrational" practices. They do not dispose of the guessing problem and are fraught with problems of their own. Yet they persist, even in the presence of more rational alternatives: Number right scoring is superior to formula scoring, and key randomization is superior to key balancing.
Kalai, G. . (2004). Social Indeterminacy. Discussion Papers. presented at the 6, Econometrica 72 (2004), 1565-1581. Retrieved from /files/dp362.pdf Publisher's VersionAbstract
An extension of Condorcet's paradox by McGarvey (1953) asserts that for every asymmetric relation R on a finite set of candidates there is a strict-preferences voter profile that has the relation R as its strict simple majority relation. We prove that McGarvey's theorem can be extended to arbitrary neutral monotone social welfare functions which can be described by a strong simple game G if the voting power of each individual, measured by the it Shapley-Shubik power index, is sufficiently small. Our proof is based on an extension to another classic result concerning the majority rule. Condorcet studied an election between two candidates in which the voters' choices are random and independent and the probability of a voter choosing the first candidate is p > 1/2. Condorcet's Jury Theorem asserts that if the number of voters tends to infinity then the probability that the first candidate will be elected tends to one. We prove that this assertion extends to a sequence of arbitrary monotone strong simple games if and only if the maximum voting power for all individuals tends to zero.
Mas-Colell, S. H., & Andreu, . (2004). Stochastic Uncoupled Dynamics and Nash Equilibrium. Discussion Papers. presented at the 9, Games and Economic Behavior 57 (2006), 286-303. Retrieved from /files/ uncoupl-st.html Publisher's VersionAbstract
In this paper we consider dynamic processes, in repeated games, that are subject to the natural informational restriction of uncoupledness. We study the almost sure convergence to Nash equilibria, and present a number of possibility and impossibility results. Basically, we show that if in addition to random moves some recall is introduced, then successful search procedures that are uncoupled can be devised. In particular, to get almost sure convergence to pure Nash equilibria when these exist, it suffices to recall the last two periods of play.
Toxvaerd, F. . (2004). Strategic Merger Waves: A Theory of Musical Chairs. Discussion Papers. presented at the 5. Retrieved from /files/dp359.pdf Publisher's VersionAbstract
This paper proposes an explanation of merger waves based on the interaction between competitive pressure and irreversibility of mergers in an uncertain environment. A set of acquirers compete over time for scarce targets. At each point in time, an acquirer can either postpone a takeover attempt, or raid immediately. By postponing the takeover attempt, an acquirer may gain from more favorable future market conditions, but runs the risk of being preempted by rivals. First, a complete information model is considered, and it is shown that the above tradeoff leads to a continuum of subgame perfect equilibria in monotone strategies that are strictly Pareto ranked. All these equilibria share the feature that all acquirers rush simultaneously in merger waves. The model is then extended to a dynamic global game by introducing slightly noisy private information about merger profitability. This game is shown to have a unique Markov perfect Bayesian equilibrium in monotone strategies, and the timing of the merger wave can thus be predicted. Last, the comparative dynamics predictions of the model are related to stylized facts.