Feeding the Cities and Greenhouse Gas Emissions - Beyond the Food Miles Approach

In this paper, we study the impact of urbanization on the location of agricultural production and the GHG emissions related to transportation activities. We develop an economic geography model where the location of agricultural activities and urban population are endogenous. We show that increasing agricultural yields induce the spatial concentration of agricultural production in the least urbanized region if agricultural transport costs are relatively low and in the most urbanized region otherwise. In addition, interregional trade in agricultural commodities is desirable to reduce GHG emissions, except when urban population is equally split between cities. However, the market may induce too much agglomeration of agricultural production when yields are high and when collection costs are low.Urbanization, agriculture location, transport, Environmental Economics and Policy, Food Security and Poverty, Q10, Q54, R12,

Competition, efficiency and collective behavior in the "El Farol" bar model

The El Farol bar model, proposed to study the dynamics of competition of agents in a variety of contexts (W. B. Arthur, Amer. Econ. Assoc. Pap. and Proc. 84, 406 (1994)) is studied. We characterize in detail the three regions of the phase diagram (efficient, inefficient and better than random) of the simplest version of the model (D. Challet and Y.-C. Zhang, Physica A, 246, 407 (1997)). The efficient region is shown to have a rich structure, which is investigated in some detail. Changes in the payoff function enhance further the tendency of the model towards a wasteful distribution of resources.Comment: 7 pages Latex, 7 Postscript figures; changed reference, acknowledgments included. Accepted for publication in Europen Physics Journal

Influence of external information in the minority game

The influence of a fixed number of agents with the same fixed behavior on the dynamics of the minority game is studied. Alternatively, the system studied can be considered the minority game with a change in the comfort threshold away from half filling. Agents in the frustrated, non ergodic phase tend to overreact to the information provided by the fixed agents, leading not only to large fluctuations, but to deviations of the average occupancies from their optimal values. Agents which discount their impact on the market, or which use individual strategies reach equilibrium states, which, unlike in the absence of the external information provided by the fixed agents, do not give the highest payoff to the collective.Comment: 8 pages, 6 figure

Greenhouse gas emissions from agriculture in the EU: A spatial assessment of sources and abatement costs

Agriculture contributes significantly to the emissions of greenhouse gases in the EU. By using a farm-type, linear-programming based model of the European agricultural supply, we first assess the initial levels of methane and nitrous oxide emissions at the regional level in the EU. For a range of CO2 prices, we assess the potential abatement that can be achieved through an IPCC-based emission tax in EU agriculture, as well as the resulting optimal mix of emission sources in the total abatement. Further, we show that the spatial variability of the abatement actually achieved at a given carbon price is large, indicating that abatement cost heterogeneity is a fundamental feature in the design of a mitigation policy. We assess the efficiency loss associated with uniform standards relative to an emission tax.Climate change, greenhouse gas emissions, agriculture, methane, nitrous oxide, European Union, marginal abatement costs, Environmental Economics and Policy, Q25, Q15,

La violencia en la escuela : detección y prevención de conductas violentas

En las sociedades actuales, debemos reconocer que la violencia atraviesa todas las esferas, ya sea económica, social, política y cultural. Para el presente trabajo, se reconoce que las relaciones sociales son siempre relaciones de poder, y como tales, siempre se hallan en ellas condiciones de opresión, abuso de autoridad y discriminación. La violencia se presenta como un fenómeno cotidiano en las prácticas sociales, se llega a naturalizar, actuando de un modo desprevenido y sorpresivo, no sólo frente a los atentados contra la propiedad, la agresión física y simbólica que se muestra a diario en los medios masivos de comunicación, sino también en otras formas como servicios públicos deficientes, pobreza, marginalidad, adicciones, entre otros. La propuesta de este trabajo es que los docentes puedan volver visibles las prácticas violentas a las que están sujetas las relaciones sociales de sus alumnos, dentro y fuera de la escuela, reconociendo inicialmente sus propias prácticas, como posibles portadoras de violencia.Fil: De Cara, Graciela B.. Universidad Nacional de San Jua

What content makes people want to use sports websites?

This study looked at sports websites to see how the variables information, humor, entertainment, community, and credibility affected sports website users’ intentions to use and re-use sports websites. Three groups of 25 and one group of 30 participants each completed a website viewing activity and corresponding survey. There were four website viewing activities (one for each group). The activities led participants on tours of ESPN.com, Deadspin.com, Football Outsiders, and Yahoo! Sports. Furthermore, the tours were designed to expose participants to the variables (as defined under disposition theory and uses and gratifications). Likewise, the corresponding survey assessed participants’ intentions to use each of the four websites based on the degrees to which they perceived each variable to be present. In addition to the surveys, the study utilized focus group discussion data as a secondary method. Five focus groups and one interviewee each answered eight open-ended questions. All answers were analyzed according to which of the variables were important to participants on sports websites. Results of the survey data showed that humor and entertainment content had the most positive effect on sports website users’ intents to use, whereas information and credibility content scored highest among the discussion participants. The community variable ranked last via both methods. The ramifications for this study are that sports websites should develop their humorous and entertaining content regarding athletes and sports figures. Website partnerships with informative and credible sites should be formed to maintain sports information links