Linking poverty, natural resources, and financial markets: a model of land use by rural households in El Salvador

This paper posits that deforestation and poverty levels are related through an inverted-U shape --the environmental Kuznets-- curve and that access to credit shifts this curve downwards, thus positively impacting natural resource uses. This hypothesis is tested using a household panel data set from El Salvador.Land Economics/Use,

New vector bosons and the diphoton excess

We consider the possibility that the recently observed diphoton excess at $\sim 750$ GeV can be explained by the decay of a scalar particle ($\varphi$) to photons. If the scalar is the remnant of a symmetry-breaking sector of some new gauge symmetry, its coupling to photons can be generated by loops of the charged massive vectors of the broken symmetry. If these new $W^\prime$ vector bosons carry color, they can also generate an effective coupling to gluons. In this case the diphoton excess could be entirely explained in a simplified model containing just $\varphi$ and $W^\prime$. On the other hand if $W^{\prime}$ does not carry color, we show that, provided additional colored particles exist to generate the required $\varphi$ to gluon coupling, the diphoton excess could be explained by the same $W^{\prime}$ commonly invoked to explain the diboson excess at $\sim 2$ TeV. We also explore possible connections between the diphoton and diboson excesses with the anomalous $t\bar{t}$ forward-backward asymmetry.Comment: Latex 8 pages, 1 figure. Extended discussion, new references. Matches published versio

Una región, cuatro velocidades

El autor identifica a dos países en la región con alto crecimiento y baja inflación, pero también observa a otras economías que no viven en el mejor de los mundos.

THE INFLUENCE OF MICROFINANCE ON THE EDUCATION DECISIONS OF RURAL HOUSEHOLDS: EVIDENCE FROM BOLIVIA

There is debate about measurement of impact and achievement of expected results of rural microfinance programs in LDCs. The paper addresses these issues using survey household data from Bolivia. Regression models examine the determinants of education outcomes for microfinance clients. The results challenge usual assumptions in program design.Teaching/Communication/Extension/Profession,

On Psych Verbs and Optional Clitic Doubling in Catalan and Other Ibero-Romance Languages

Although undesired under a theoretical viewpoint, natural languages often show cases of "true" optionality. According to a reformulation of the Interface Hypothesis (Sorace 2006), highly complex constructions are more susceptible to optionality and change. Psych verbs that select a subject dative experiencer fall under this definition. Ibero-Romance languages use different strategies to reduce this morphosyntactic inconsistency. Whereas Catalan and Spanish reinforce the deviant construction through additional morphological markers (dative clitic doubling and subsequent grammaticalization of the clitic as subject-verb agreement marker), Portuguese avoids inherent datives at all, using structural case instead. These innovations in argument structure have significant consequences: clitic doubling with full DPs and the grammaticalization of the clitic pronouns are blocked, in contrast to Catalan and Spanish. It becomes evident that a closer look at how argument structure is codified in the lexicon is needed in order to better understand processes of language change.Tot i ser poc desitjat en la teoria, les llengües naturals presenten sovint casos de «veritable» opcionalitat. Seguint una reformulació de la Hipòtesi de la Interfície (Sorace 2006), les construccions amb major grau de complexitat són susceptibles d'ocasionar opcionalitat i canvi lingüístic. Els verbs psicològics que seleccionen subjectes experimentadors en datiu en són un exemple. Les llengües iberoromàniques fan servir diverses estratègies per reduir aquesta inconsistència morfosintàctica. El català i l'espanyol reforcen aquestes construccions a través d'un marcatge morfològic addicional (el doblatge i posterior gramaticalització de clítics datius com a marcadors de concordança de subjecte) -el portuguès rebutja d'entrada el cas inherent i el substitueix per cas estructural. Aquesta innovació en l'estructura argumental comporta altres canvis significatius: el doblatge de clítics amb SD plens i la gramaticalització dels pronoms clítics queden bloquejats, al contrari que en català i espanyol. És evident que cal considerar amb més deteniment com es materialitza al lèxic l'estructura argumental per comprendre millor el canvi lingüístic

Powder bed fusion for electromechanical plastic components in high voltage electric vehicle applications.

Over the years, Injection Molding has been the ruling process to manufacture polymeric components for the automotive industry. By this process, excellent properties and fully dense parts can be achieved. Injection Molding can be pricey if a production batch size is not big enough to justify the high costs of the molds. With the increasing demand for Electric Vehicles, the need for plastic parts with a combination of good mechanical and dielectric properties could grow significantly. When low production volumes are required, Additive Manufacturing of polymeric components can be considered as an alternative to Injection Molding. For this to happen, the behavior of parts produced by Additive Manufacturing need to be tested in order to demonstrate their mechanical capabilities and as electrical insulators within a high voltage level, at which components and devices utilized in Electric Vehicle applications are tested. In this work, tensile and electrical insulation specimens manufactured from polyamide (PA12) by Selective Laser Sintering (SLS) and HP- Multi Jet Fusion (MJF) in three build orientations were tested and compared to equivalent specimens produced by Injection Molding. For analyzing their mechanical properties, tensile tests were carried out according to the ISO-527 standard. To evaluate their efficiency as electrical insulators, voltage withstand (HIPOT) tests were performed to the specimens at a voltage level of 4kV AC and within a temperature range between 20 and 100°C. The test results obtained by the tensile experiments denoted that the parts produced by Powder Bed Fusion for these experiments presented brittle behavior at fracture, with a maximum elongation at break between 10-26%. The maximum achieved tensile strength values represented almost 74% of the ones obtained by the injection molded equivalent specimens. As electrical insulators, the HIPOT test results showed that SLS specimens with a thickness of 2mm withstood a 4kV AC voltage load comparably as the injection molded parts. The Radiation- Absorbing Material present in the HP-MJF fusing agent could be a contributor for dielectric breakdown on the tested specimens. Therefore, the applicability of the HP-MJF process is questionable for high voltage environments and within the test conditions employed

The use of Mexican private medical services by American nationals in the border city of Tijuana. An appraisal of Mexico's comparative advantages over the United States of America

Starting from the hypothesis that Mexico has a comparative advantage over the United States in the provision of medical services, this thesis analyses the phenomenon that is causing American nationals to travel to Mexico seeking medical services, and the main characteristics of this situation. Its main purpose is to determine the possible existence of factors related to comparative advantages in the provision of medical services in Mexico. Therefore different theories of comparative advantage are analyzed in order to propose a model that can be easily applied for medical services. After this, several studies made on health issues along the U.S.- Mexico border are reviewed in order to create a general scenario. Later on it focuses in the use of medical services by American nationals in the Mexican city of Tijuana, in Baja California. This city was selected due to its known close socio-economic relationship to the American city of San Diego in California, and for being the busiest border crossing in the region, with 5 to 6 million monthly border crossings. By using data collected from 10 clinics and hospitals located in the city of Tijuana selected at random, the thesis is able to identify the necessary elements in order to prove the existence of comparative advantages in the provision of specific medical services from the private sector. And finally the thesis is able to demonstrate that, although more studies need to be made, for this case it can be said that Mexico does have comparative advantages over the United States in the provision of specific medical services, such as availability of physicians, good quality and low costs. It is suggested that this issue can become a crucial element for regional development, and mentions possible lines of action in order to promote private medical services towards an export oriented industry, as well as the possible risks involved