2005
Peters, Bezalel Peleg, and Hans.
“Nash Consistent Representation Of Effectivity Functions Through Lottery Models”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractEffectivity functions for finitely many players and alternatives are considered. It is shown that every monotonic and superadditive effectivity function can be augmented with equal chance lotteries to a finite lottery model - i.e., an effectivity function that preserves the original effectivity in terms of supports of lotteries - which has a Nash consistent representation. In other words, there exists a finite game form which represents the lottery model and which has a Nash equilibrium for any profile of utility functions, where lotteries are evaluated by their expected utility. No additional condition on the original effectivity function is needed.
Gavison, Ruth .
“Neve-Shalom/Wahat-Al-Salam School: An Island Of Coexistence In A Sea Of Conflict, The”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractThese two papers (one in English and one in Hebrew) describe the unique educational experience of the Neve Shalom school, which is a fully integrated Jewish-Arab school within a system where Jews and Arabs regularly study in separate schools and languages. They are similar but have different emphases since the audiences are expected to be different in terms of background knowledge and familiarity with facts and situations. The paper studies the way the school handles issues of culture, language, religion and national identity. It then analyzes the school and makes suggestions concerning both the improvement of the effectiveness of the school itself and what can be learned from its experience to the educational system in Israel as a whole.
Kalai, Gil .
“Noise Sensitivity And Chaos In Social Choice Theory”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractIn this paper we study the social preferences obtained from monotone neutral social welfare functions for random individual preferences. It turns out that there are two extreme types of behavior. On one side, there are social welfare functions, such as the majority rule, that lead to stochastic stability of the outcome in terms of perturbations of individual preferences. We identify and study a class of social welfare functions that demonstrate an extremely different type of behavior which is a completely chaotic: they lead to a uniform probability distribution on all possible social preference relations and, for every''>0, if a small fraction'' of individuals change their preferences (randomly) the correlation between the resulting social preferences and the original ones tends to zero as the number of individuals in the society increases. This class includes natural multi-level majority rules.
Sagi, Ilan Yaniv, and Michal.
“On Not Wanting To Know And Not Wanting To Inform Others: Choices Regarding Predictive Genetic Testing”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractRecent advancement in genetics testing for late-onset diseases raises fundamental decision dilemmas. The first study surveyed people's willingness to undergo predictive testing to find out about their own predisposition for certain incurable, late-onset diseases. The second study investigated the respondents' willingness to be tested as a function of the base rate of the disease, test diagnosticity, and the availability of treatment for the disease. In addition we surveyed (in the first study) people's willingness to disclose to others personal information about their genetic predisposition. The findings show that people often prefer not to know, as if they are choosing "protective ignorance". Respondents' verbal justifications of their choices were also analyzed. Respondents offered emotional, cognitive-instrumental, and strategic reasons for their preferences. The findings are compared with other issues in behavioral decision theory, including attitudes towards uncertainty and desire for control. The implications of the findings for policies and legislation on genetic tests are also considered.
Nisan, Liad Blumrosen, and Noam.
“On The Computational Power Of Iterative Auctions I: Demand Queries”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractWe study the computational power and limitations of iterative combinatorial auctions. Most existing iterative combinatorial auctions are based on repeatedly suggesting prices for bundles of items, and querying the bidders for their "demand under these prices. We prove several results regarding such auctions that use a polynomial number of demand queries: (1) that such auctions can simulate several other natural types of queries; (2) that such auctions can solve linear programming relaxations of winner determination problems; (3) that they can approximate the optimal allocation as well as generally possible using polynomial communication or computation, while weaker types of queries can not do so. We also initiate the study of how can the prices of bundles be represented when they are not linear, and show that the "default representation has severe limitations.
Nisan, Liad Blumrosen, and Noam.
“On The Computational Power Of Iterative Auctions Ii: Ascending Auctions”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractWe embark on a systematic analysis of the power and limitations of iterative ascending-price combinatorial auctions. We prove a large number of results showing the boundaries of what can be achieved by different types of ascending auctions: item prices vs. bundle prices, anonymous prices vs. personalized prices, deterministic vs. non-deterministic, ascending vs. descending, preference elicitation vs. full elicitation, adaptive vs. non-adaptive, and single trajectory vs. multi trajectory. Two of our main results show that neither ascending item-price auctions nor ascending anonymous bundle-price auctions can determine the optimal allocation among general valuations. This justifies the use of personalized bundle prices in iterative combinatorial auctions like the FCC spectrum auctions.
Yaniv, Ilan .
“Receiving Other People's Advice: Influence And Benefit”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractSeeking advice is a basic practice in making real life decisions. Until recently, however, little attention has been given to it in either empirical studies or theories of decision making. The studies reported here investigate the influence of advice on judgment and the consequences of advice use for judgment accuracy. Respondents were asked to provide final judgments on the basis of their initial opinions and advice presented to them. The respondents' weighting policies were inferred. Analysis of the these policies show that (a) the respondents tended to place a higher weight on their own opinion than on the advisor's opinion (the self/other effect); (b) more knowledgeable individuals discounted the advice more; (c) the weight of advice decreased as its distance from the initial opinion increased; and (d) the use of advice improved accuracy significantly, though not optimally. A theoretical framework is introduced which draws in part on insights from the study of attitude change to explain the influence of advice. Finally the usefulness of advice for improving judgment accuracy is considered.
Toxvaerd, Flavio .
“Record Breaking And Temporal Clustering”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractCasual observation suggests that athletics records tend to cluster over time. After prolonged periods without new records, a record breaking performance spurs other athletes to increase effort and thereby repeatedly set new standards. Subsequently, record breaking subsides and the pattern repeats itself. The clustering hypothesis is tested for the mile run, the marathon, the world hour record and long jump. For all four disciplines, the hypothesis of non-clustering is rejected at the 4 level or below. A theoretical rationale for this phenomenon is provided through a model of social learning under limited awareness. The agents are assumed to be unaware of the true limits to performance and to take the current record as the upper bound. The observation of a record breaking achievement spurs the agents to try harder and thus temporarily increase the probability of new records. Subsequently, record breaking trails off and the process is repeated.
Abba M. Krieger, Moshe Pollak, and Ester Samuel-Cahn.
“Select Sets: Rank And File”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractIn many situations, the decision maker observes items in sequence and needs to determine whether or not to retain a particular item immediately after it is observed. Any decision rule creates a set of items that are selected. We consider situations where the available information is the rank of a present observation relative to its predecessors. Certain "natural" selection rules are investigated. Theoretical and Monte Carlo results are presented pertaining to the evolution of the number of items selected, measures of their quality and the time it would take to amass a group of a given size. A comparison between rules is made, and guidelines to the choice of good procedures are offered.
Gorodeisky, Ziv .
“Stability Of Mixed Equilibria”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractWe consider stability properties of equilibria in stochastic evolutionary dynamics. In particular, we study the stability of mixed equilibria in strategic form games. In these games, when the populations are small, all strategies may be stable. We prove that when the populations are large, the unique stable outcome of best-reply dynamics in 2 x 2 games with a unique Nash equilibrium that is completely mixed is the mixed equilibrium. The proof of this result is based on estimating transition times in Markov chains.
Kalai, Gil .
“Thoughts On Noise And Quantum Computation”.
Discussion Papers 2005. Web.
Publisher's VersionAbstract'We will try to explore, primarily from the complexity-theoretic point of view, limitations of error-correction and fault-tolerant quantum computation. We consider stochastic models of quantum computation on n qubits subject to noise operators that are obtained as products of tiny noise operators acting on a small number of qubits. We conjecture that for realistic random noise operators of this kind there will be substantial dependencies between the noise on individual qubits and, in addition, the dependence structure of the noise acting on individual qubits will necessarily depend (systematically) on the dependence structure of the qubits themselves. The main hypothesis of this paper is that these properties of noise are sufficient to reduce quantum computation to probabilistic classical computation. Some potentially relevant mathematical issues and problems will be described. Our line of thought appears to be related to that of physicists Alicki, Horodecki, Horodecki and Horodecki [AHHH].'
Nitzan, Noa .
“Tight Correlated Equilibrium”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractA correlated equilibrium of a strategic form n-person game is called tight if all the incentive constraints are satisfied as equalities. The game is called tight if all of its correlated equilibria are tight. This work shows that the set of tight games has positive measure.
Shahar Dobzinski, Noam Nisan, and Michael Schapira.
“Truthful Randomized Mechanisms For Combinatorial Auctions”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractWe design two computationally-efficient incentive-compatible mechanisms for combinatorial auctions with general bidder preferences. Both mechanisms are randomized, and are incentive-compatible in the universal sense. This is in contrast to recent previous work that only addresses the weaker notion of incentive compatibility in expectation. The first mechanism obtains an O('ˆ\v sm)-approximation of the optimal social welfare for arbitrary bidder valuations – this is the best approximation possible in polynomial time. The second one obtains an O(log2 m)-approximation for a subclass of bidder valuations that includes all submodular bidders. This improves over the best previously obtained incentive-compatible mechanism for this class which only provides an O('ˆ\v sm)-approximation.
Ein-Ya, Gura .
“Using Game Theory To Increase Students' Motivation To Learn Mathematics”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractThis paper reports an attempt to teach game theory in order to increase students' motivation to learn mathematics. A course in game theory was created in order to introduce students to new mathematical content presented in a different way.
Dreze, R. J. Aumann, and J. H. “When All Is Said And Done, How Should You Play And What Should You Expect?”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractModern game theory was born in 1928, when John von Neumann published his Minimax Theorem. This theorem ascribes to all two-person zero-sum games a value-what rational players may expect-and optimal strategies-how they should play to achieve that expectation. Seventy-seven years later, strategic game theory has not gotten beyond that initial point, insofar as the basic questions of value and optimal strategies are concerned. Equilibrium theories do not tell players how to play and what to expect; even when there is a unique Nash equilibrium, it it is not at all clear that the players "should" play this equilibrium, nor that they should expect its payoff. Here, we return to square one: abandon all ideas of equilibrium and simply ask, how should rational players play, and what should they expect. We provide answers to both questions, for all n-person games in strategic form.
Samuel-Cahn, Ester .
“When Should You Stop And What Do You Get? Some Secretary Problems”.
Discussion Papers 2005. Web.
Publisher's VersionAbstract{A version of a secretary problem is considered: Let Xj
Flekser, Judith Avrahami, and Oren.
“With The Eye Being A Ball, What Happens To Fixational Eye Movements In The Periphery?”.
Discussion Papers 2005. Web.
Publisher's VersionAbstractAlthough the fact that the eye is moving constantly has been known for a long time, the role of fixational eye movements (FEM) is still in dispute. Whatever their role, it is structurally clear that, since the eye is a ball, the size of these movements diminishes for locations closer to the poles. Here we propose a new perspective on the role of FEM from which we derive a prediction for a three-way interaction of a stimulus' orientation, location, and spatial frequency. Measuring time-to-disappearance for gratings located in the periphery we find that, as predicted, gratings located to the left and right of fixation fade faster when horizontal than when vertical in low spatial frequencies and faster when vertical than when horizontal in high spatial frequencies. The opposite is true for gratings located above and below fixation.
Nisan, Noam, and Shimon Schocken.
The Elements Of Computing Systems. The MIT Press, 2005. Print.
In the early days of computer science, the interactions of hardware, software, compilers, and operating system were simple enough to allow students to see an overall picture of how computers worked. With the increasing complexity of computer technology and the resulting specialization of knowledge, such clarity is often lost. Unlike other texts that cover only one aspect of the field, The Elements of Computing Systems gives students an integrated and rigorous picture of applied computer science, as its comes to play in the construction of a simple yet powerful computer system.Indeed, the best way to understand how computers work is to build one from scratch, and this textbook leads students through twelve chapters and projects that gradually build a basic hardware platform and a modern software hierarchy from the ground up. In the process, the students gain hands-on knowledge of hardware architecture, operating systems, programming languages, compilers, data structures, algorithms, and software engineering. Using this constructive approach, the book exposes a significant body of computer science knowledge and demonstrates how theoretical and applied techniques taught in other courses fit into the overall picture.Designed to support one- or two-semester courses, the book is based on an abstraction-implementation paradigm; each chapter presents a key hardware or software abstraction, a proposed implementation that makes it concrete, and an actual project. The emerging computer system can be built by following the chapters, although this is only one option, since the projects are self-contained and can be done or skipped in any order. All the computer science knowledge necessary for completing the projects is embedded in the book, the only pre-requisite being a programming experience.The book's web site provides all tools and materials necessary to build all the hardware and software systems described in the text, including two hundred test programs for the twelve projects. The projects and systems can be modified to meet various teaching needs, and all the supplied software is open-source.
מפה, .
צמחי ישראל. 2005. Print.
צמחי ישראל הוא מדריך שימושי המאפשר את זיהוים של צמחי הבר הנפוצים בישראל בדרך חזותית פשוטה. זהו כלי עזר רב-ערך וחיוני לכל מי שמתעניין בצמחי ישראל ומבקש להעמיק את ידיעותיו בתחום. לקסיקון מפה: צמחי ישראל מביא את תיאורם של החשובים והנפוצים בצמחי הארץ שהים מקובצים בקבוצות לפי צבע פרחיהם. כל ערך בלקסיקון מביא תצלום ותיאור מלא של הצמח בנדון בו, מפת תפוצה ו"סגרל פריחה" של הצמח. ומידע בסיסי על מינים קרובים לצמח. בסך הכל מובאים בספר תיאורים של יותר מ-800 מיני צמחים, ושל עוד כ-1,000 מיני צמחים קרובים להם. בנוסף לכך הספר מביא מידע מרתק על עוד נושאים רבים אחרים. מאסטרטגיות רביית והגנה של צמחים, דרך פרסום ורמייה בצמחים, ועד השימוש שניתן לעשות ברבים מהצמחים המתוארים בספר במטבח וברפואה.