Convergence in Models with Bounded Expected Relative Hazard Rates

We provide a general framework to study stochastic sequences related to individual learning in economics, learning automata in computer sciences, social learning in marketing, and other applications. More precisely, we study the asymptotic properties of a class of stochastic sequences that take values in $[0,1]$ and satisfy a property called "bounded expected relative hazard rates." Sequences that satisfy this property and feature "small step-size" or "shrinking step-size" converge to 1 with high probability or almost surely, respectively. These convergence results yield conditions for the learning models in B\"orgers, Morales, and Sarin (2004), Erev and Roth (1998), and Schlag (1998) to choose expected payoff maximizing actions with probability one in the long run.Comment: After revision. Accepted for publication by Journal of Economic Theor

Strategic truth and deception

We study strategic communication in a sender-receiver gamein which the sender sends a message about the observed quality ofthe good to the receiver who may accept or reject the good without knowing the true quality or the sender's type. The game has infinitely many perfect Bayesian Nash equilibria. An equilibrium refinement identifies a unique class of equilibria that are outcome equivalent to the equilibrium in which the neutral sender always tells the truth and the biased sender adopts a feigning strategy to disguise himself by not fully exaggerating about the quality of the good.Cheap Talk, Feigning Strategy, Strategic Information Transmission.

Hydrological controls on nutrient exportation from old-growth evergreen rainforests and Eucalyptus nitens plantation in headwater catchments at Southern Chile

Soil cover disturbances have a direct effect on biogeochemistry, potentially enhancing nutrient loss, land degradation and associated changes in ecosystem services and livelihood support. The objective of this study was to assess how canopy affected throughfall chemistry and how hydrology affected stream nutrient load responses in two watersheds dominated by native old-growth evergreen rainforest (NF) and exotic plantation of Eucalyptus nitens (EP), located at the Coastal mountain range of southern Chile (40˚S). We measured nitrogen (NO3-N, NH4-N, Organic-N, Total-N) and total phosphorus (Total-P) at catchment discharge, and δ18O in throughfall precipitation and stream discharge in both catchments, in order to separate throughfall (or new water) contributions during storm events. It was hypothesized that all nutrients showed an increase in concentration as discharge increased (or enhanced hydrological access), in EP; but not in NF. Our results indicated that Organic-N, Total-N and Total-P concentrations were positively related to discharge. However, 3 NO− -N showed a negative correlation with catchment discharge

Clean Development Mechanism Projects in Latin America : beyond reducing CO2 (e) emissions. A case study in Chile

The Clean Development Mechanism (CDM) was created to compensate underdeveloped countries for their contribution to mitigate climate change. Under these rules, those projects showing the lower cost, in terms of investment, for each tonne of CO2 (e) saved, will be the ones selected. However, even if this selection process seems quite rational, it can result in a suboptimal allocation of resources, when other impacts of these projects, also having to do with social welfare, are considered. This point is illustrated in this paper by comparing the financial cost of CER credits of two current CDM projects in Chile, the Santa Marta Landfill Gas Capture Project and the Corneche‐Los Guindos Methane Capture from Swine Manure Project, with that of a third, “virtual” project, the upgrading of the Renca Generation Plant in Santiago de Chile to a gas fired combined cycle (CCGT) Plant. Even if this third project is much less efficient in financial terms, it shows a very important ancillary benefit: its impact on human health. When this impact is introduced, the result, as expected, is a drastic change in the relative social profitability of the three projects

Clean Development Mechanism Projects in Latin America : beyond reducing CO2 (e) emissions. A case study in Chile

The Clean Development Mechanism (CDM) was created to compensate underdeveloped countries for their contribution to mitigate climate change. Under these rules, those projects showing the lower cost, in terms of investment, for each tonne of CO2 (e) saved, will be the ones selected. However, even if this selection process seems quite rational, it can result in a suboptimal allocation of resources, when other impacts of these projects, also having to do with social welfare, are considered. This point is illustrated in this paper by comparing the financial cost of CER credits of two current CDM projects in Chile, the Santa Marta Landfill Gas Capture Project and the Corneche‐Los Guindos Methane Capture from Swine Manure Project, with that of a third, “virtual” project, the upgrading of the Renca Generation Plant in Santiago de Chile to a gas fired combined cycle (CCGT) Plant. Even if this third project is much less efficient in financial terms, it shows a very important ancillary benefit: its impact on human health. When this impact is introduced, the result, as expected, is a drastic change in the relative social profitability of the three projects

Efectos del te negro (Camellia sinensis) sobre el flujo salival, capacidad Buffer y PH

73 p.INTRODUCCIÓN: El té es mundialmente la segunda bebida más consumida, contribuye a reducir riesgo de varias enfermedades. La saliva, un elemento esencial en la preservación de salud oral, puede verse alterada por diversos factores, entre ellos, el consumo de infusiones, en cuanto a flujo, pH y capacidad buffer, constituyendo un factor predisponente o no a la caries. OBJETIVOS: Determinar el efecto del te negro en el flujo, pH y capacidad buffer en la saliva. MATERIALES y METODO: La muestra fue de 38 sujetos con bajo riesgo cariogenico y sanos, se tomaron tres muestra de saliva, basal, post-ingesta de agua y de té (Supremo®, a 50°C y sin endulzantes) en las que se determinó, flujo salival (ml/min), pH con un potenciómetro (PL-600Lab PH meter) y capacidad buffer según método de Ericsson para saliva no estimulada. Las mediciones del estudio se compararon con las pruebas estadística, para muestras repetidas, diseño en bloques aleatorios y ANOVA, con sofware SPSS 15.0. RESULTADOS: Al comparar las medianas de las muestras, basal, post-ingesta de agua y de té de flujo salival (0,50 / 0,37 / 0,47 ml/min.) se observa que existe diferencia significativa tendiente a recuperar el flujo con el té a valores casi basales; respecto al pH salival presenta medianas de 7.22, 7.20 y 7.22 respectivamente mostrando un comportamiento similar del flujo pero no significativo; por último al comparar las medianas de la capacidad buffer ( 4.75 / 4.10 / 3.10 ) muestra que tanto la ingesta de agua, como de té disminuye la capacidad buffer significativamente. CONCLUSIÓN: La ingesta del té negro tiende a recuperar el flujo y ph post ingesta de agua a valores casi basales y disminuye la capacidad buffer de la saliva. Palabras clave: pH salival, capacidad buffer, té negro

Imitation in Heterogeneous Populations

We study a boundedly rational model of imitation when payoff distributions of actions differ across types of individuals. Individuals observe others’ actions and payoffs, and a comparison signal. One of two inefficiencies always arises: (i) uniform adoption, i.e., all individuals choose the action that is optimal for one type but sub-optimal for the other, or (ii) dual incomplete learning, i.e., only a fraction of each type chooses its optimal action. Which one occurs depends on the composition of the population and how critical the choice is for different types of individuals. In an application, we show that a monopolist serving a population of boundedly rational consumers cannot fully extract the surplus of high-valuation consumers, but can sell to consumers who do not value the good

Toxicidad y teratogénesis por arsénico en aguas en el pez cebra (Danio rerio)

El objetivo del trabajo fue estudiar los daños teratogénicos y la inducción de micronúcleos en células branquiales de peces cebra (Danio rerio) por presencia de arsénico en las aguas. Fueron mantenidos en aguas bicarbonatadas cálcicas magnésicas de un pozo de referencia y del pozo "Zimapán 5", del Municipio Zimapán, Estado de Hidalgo, México. Este último, con un contenido de arsénico que varía de 0,395-0,630 mg/L. Para el estudio de genotoxicidad se evaluaron durante 180 días en 3 tratamientos: agua del pozo de referencia (control negativo, sin As), agua del pozo de referencia adicionada con 5,0 mg As (V)/L (control positivo), y en agua del pozo "Zimapán 5", colocándose 65 especimenes por tratamiento. Después de 30 días hubo una disminución de As en el agua del control positivo de 1092,65 ppb (36,42 ppb/día) mientras en pescados hubo un incremento de 523,81 ppb (17,46 ppb/día). Para el agua del pozo "Zimapán 5" hubo una disminución de 211,40 ppb (7,04 ppb/día), y en pescados hubo un incremento de 74,73 ppb (2,49 ppb/día). Este resultado pone de manifiesto el alto grado de bioacumulación de As en el pez, que en relación al control negativo muestra que es 2,54 veces mayor. En relación a la frecuencia de inducción de micronúcleos en células branquiales, al final de los 180 días en el control negativo hubo una generación espontánea de 0,8 micronúcleos/1000 células, en el control positivo hubo una frecuencia de inducción de micronúcleos 163,5 veces mayor que en el control negativo, mientras que en los peces expuestos al agua del pozo "Zimapán 5" fue 56,25 veces mayor con respecto al mismo. Estos resultados demuestran la genotoxicidad del As en Danio rerio. Para el estudio de teratogénesis, se colocó una hembra y un macho en apareamiento en las mismas condiciones de los tratamientos, obteniendo que a mayor concentración de As en el agua mayor porcentaje de huevos no viables, menor porcentaje de huevos viables y de eclosión, mayor porcentaje de alevines recién eclosionados y juveniles con malformaciones, y menor porcentaje de juveniles sobrevivientes