Field Centipedes

We conduct a field experiment in which highly-ranked chess players play the centipede game in a natural setting. This game represents one of the main paradoxes of backward induction. In the experiment two players alternately are faced with the decision of either taking an exponentially growing pile of money and ending the game, or letting the other player make the decision. The player who decides to stop the game takes the larger portion of the pile, and the other player gets the remaining amount. All standard equilibrium concepts dictate that the player who decides first must stop the game immediately. There is vast experimental evidence, however, that this rarely occurs. Contrary to this evidence our results show that 69% of chess players stop the game immediately. When we restrict attention to chess Grandmasters this percentage escalates to 100%. We also conduct standard laboratory experiments where college students and chess players play ten repetitions of the game. We find that chess players playing versus other chess players rapidly converge to the equilibrium outcome, whereas students playing versus other students systematically depart from it. However, when students play against chess players the occurrence of the backward induction outcome increases tenfold.Rationality, centipede game, experiments, chess players.

The Measurement of Intellectual Influence

We examine the problem of measuring influence based on the information contained in the data on the communications between scholarly publications, judicial decisions, patents, web pages, and other entities. The measurement of influence is useful to address several empirical questions such as reputation, prestige, aspects of the diffusion of knowledge, the markets for scientists and scientific publications, the dynamics of innovation, ranking algorithms of search engines in the World Wide Web, and others. In this paper we ask why any given methodology is reasonable and informative applying the axiomatic method. We find that a unique ranking method can be characterized by means of five axioms: anonymity, invariance to citation intensity, weak homogeneity, weak consistency, and invariance to splitting of journals. This method is easily implementable and turns out to be different from those regularly used in social and natural sciences, arts and humanities, and computer science.Intellectual Influence, Citations, Ranking Methods, Consistency.

EXPERIENTIA DOCET: PROFESSIONALS PLAY MINIMAX IN LABORATORY EXPERIMENTS

We study how professional players and college students play zero-sum two-person strategic games in a laboratory setting. We first ask professionals to play a 2x2 game that is formally identical to a strategic interaction situation that they face in their natural environment. Consistent with their behavior in the field, they play very close to the equilibrium of the game. In particular, (i) they equate their strategies' payoffs to the equilibrium ones, and (ii) they generate sequences of choices that are serially independent. In sharp contrast, however, we find that college students play the game far from the equilibrium predictions. We then study the behavior of professional players and college students in the classic O'Neill's 4x4 zero-sum game, a game that none of the subjects have encountered previously, and find the same differences in the behavior of these two pools of subjects. The transfer of skills and experience from the familiar field to the unfamiliar laboratory observed for professional players is relevant to evaluate the circumstances under which behavior in a laboratory setting may be a reliable indicator of behavior in a naturally occurring setting. From a cognitive perspective, it is useful for research on recognition processes, intuition, and similarity as a basis for inductive reasoning.Laboratory Experiments, Minimax, Experience, Cognition.

Rejecting Small Gambles Under Expected Utility

This paper contributes to an important recent debate around expected utility and risk aversion. Rejecting a gamble over a given range of wealth levels imposes a lower bound on risk aversion. Using this lower bound and empirical evidence on the range of the risk aversion coefficient, we calibrate the relationship between risk attitudes over small-stakes and large-stakes gambles. We find that rejecting small gambles is consistent with expected utility, contrary to a recent literature that concludes that expected utility is fundamentally unfit to explain decisions under uncertainty. Paradoxical behavior is only obtained when calibrations are made in a region of the parameter space that is not empirically relevant.Risk Aversion, Expected Utility

Developing of speaking skills in EFL senior learners A1

El aprendizaje de lenguas extranjeras ha tenido un gran auge y gran visibilidad desde el inicio de la globalización, así mismo los desarrollos de programas de aprendizaje de una lengua extranjera por parte de editoriales, universidades, centros de lengua, apps, páginas web han desarrollado y gamificado ampliamente este particular, pero frente a la necesidad e interés por parte de las personas mayores por aprender lenguas son escasos los programas que podrían ajustarse a dicho propósito, por ello se hace un proyecto de investigación que propone usar los principios de la andragogía y del método espiral como un pequeño aporte a un mundo lleno de posibilidades para las personas mayores. Este proyecto se hace con la participación de personas mayores voluntarias y el soporte de las herramientas ofimáticas de la Universidad Nacional Abierta y a Distancia. Los registros se hicieron con base en instrumentos como entrevistas, grabaciones de video, y encuestas resueltos por los participantes de esta.Learning English as a foreign language is one of the most relevant objectives for schools, parents, companies, ministries of education, and all productive fields in our country. In Colombia, there are few published research experiences addressing this specific field; therefore, it is worthwhile to embark on pertinent and innovative research projects in the context of teaching English to the elderly. This research project aims to propose a different field of instruction from the traditional choices usually offered to senior learners of English; in particular, it seeks to provide them with the opportunity to learn English within a classroom environment that values their needs and characteristics. The current research determined that some principles of andragogy and spiral syllabus design are not related to the development of speaking skills in EFL learners, but they can widely improve their interest,motivation, and progress

The measurement of intellectual influence

We examine the problem of measuring influence based on the information contained in the data on the communications between scholarly publications, judicial decisions, patents, web pages, and other entities. The measurement of influence is useful to address several empirical questions such as reputation, prestige, aspects of the diffusion of knowledge, the markets for scientists and scientific publications, the dynamics of innovation, ranking algorithms of search engines in the World Wide Web, and others. In this paper we ask why any given methodology is reasonable and informative applying the axiomatic method. We find that a unique ranking method can be characterized by means of five axioms: anonymity, invariance to citation intensity, weak homogeneity, weak consistency, and invariance to splitting of journals. This method is easily implementable and turns out to be different from those regularly used in social and natural sciences, arts and humanities, and computer science

Marginación social por falta de acceso al agua potable

Fil: Vázquez, Cristina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Química; ArgentinaFil: Palacios, Oscar. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Gestión Industrial; ArgentinaA partir de denuncias de los vecinos del barrio Los Álamos, localidad de Virrey del Pino,\nen el partido de La Matanza, sobre la posible contaminación del agua que consumían, a\nun equipo de profesores y estudiantes de la Facultad de Ingeniería de la UBA se le\nencomendó un estudio socio ambiental en una comunidad que sufría problemas\ngastrointestinales, respiratorios y cutáneos. Los resultados de los estudios revelaron que\nel agua no era potable, que contenía arsénico, nitrato, Salmonella, aeruginosa y\nScherichia colli, una prueba inequívoca del mal mantenimiento de los pozos y de su\nproximidad a las cámaras sépticas

Radiocarbon dating of the last glaciation in Peru

In the Cordillera Vilcanota and the vicinity of the Quelccaya ice cap, near lat 14°S in eastern Peru, the last glaciation culminated sometime between about 28,000 and 14,000 B.P. Alpine glaciers were then only about half as long as during an earlier glaciation of unknown date. A rather minor readvance of the Quelccaya ice cap was in progress about 11,500 B.P. and culminated about 11,000 B.P., some 500 to 800 yr before the Younger Dryas Stade in Europe. By 10,000 B.P., the Quelccaya ice cap was little if any larger than it is today, and it was smaller than it is today between about 2700 and 1600 B.P. Glacier fluctuations during the interval 10,000 to 3000 B.P. have not yet been determined. A “Little Ice Age” maximum culminated between 600 and 300 B.P. The relative importance of changes in temperature and precipitation in causing these glacier variations is uncertain

Los artefactos líticos del Alero Carriqueo : informe de avance 2010

El denominado alero Carriqueo se ubica en Nordpatagonia, en la cuenca del río Limay. El actual sitio arqueológico fue recurrentemente habitado durante un amplio período. Hasta el presente el registro arqueológico, abundante y variado, se puede vincular al período ceramolítico de la región. En este trabajo brindamos información acerca de los resultados obtenidos luego del estudio morfológico-descriptivo de una muestra de artefactos líticos que hemos dividido en débitage lato sensu por un lado (débitage stricto sensu más las matrices bifaciales y los núcleos) y por el otro, en instrumentos. Todos proceden de las excavaciones realizadas en el sitio hasta la actualidad.The Carriqueo Nordpatagonia rock shelter is located in the Lima)/ River basin. The current archaeological site was occupied repeatedly over an extended period. So far the archaeological record, generous and varied, can be linked to the region ceramolítico period. In this paper we provide information about the results after morphologicaldescriptive study of a sample of lithic debitage we divided into sensu lato on one side (sensu stricto debitage more bifacial matrix and cores) and the other in instruments. All come from the excavations at the site until today.Fil: Palacios, Oscar M. . Universidad de Buenos AiresFil: Ramos, Mariano S. . Universidad Nacional de Lujá