Monetary Policy and Commodity Prices: an endogenous analysis using an SVAR approach

This work analyzes the relationship between real interest rates and commodity prices. According to Frankel’s hypothesis (1986-2006): "low real interest rates lead to high real commodity prices". However, some empirical evidence suggests that commodity prices can predict monetary policy. In this way, there is an endogeneity between commodity prices and monetary policy. Using Frankel’s model we include a Taylor rule equation in this theoretical model, which let us analyze the endogeneity problem. In order to find empirical support of this model, we estimate SVAR and, using quarterly data from 1962:Q1 to 2009:Q1, we find that the overshooting of commodity prices to 1% increase of real interest rate can be a minimum of 2.86% and a maximum of 5.97% depending on the chosen model. The increase of real interest rate given a 1% increase in commodity prices is positive and significant but of small magnitude (0.20% - 0.05%).Monetary Policy, Commodity Prices, SVAR models. Classification JEL: C32, E31, E52, G14

Structural models of random packing of spheres extended to bricks: Simulation of the nanoporous calcium silicate hydrates

Structure simulation algorithms of random packing of spheres and bricks have been developed. These algorithms were used to reproduce the nanostructure of the cementitious calcium silicate hydrates. The textural parameters (specific surface area, porosity, pore size, etc.) of a calcium silicate hydrates (C-S-H) sample, the main binding phase of hydrated cements, have been derived from N2-physisorption experiments. At the same time, these parameters have been simulated by using a sphere-based structural model, where the spheres are randomly packed according to several hierarchical levels. The corresponding algorithm has been extended for managing cuboids instead of spheres. The C-S-H sample density is successfully predicted by considering the presence of water in pores defined by the sphere network within 10-nm-size globules and assuming a tobermorite-like skeleton. Simulations with bricks (321.4nm3) yield also textural parameters that are consistent with N2-physisorption data, but with a globule radius (22nm) twice as big as that obtained when using spheres.European Union MRTN-CT-2006-03586

Aportes postcoloniales (latinoamericanos) al estudio de los movimientos sociales

Desde el giro de los ochenta hasta hoy, los análisis de la acción colectiva tienden a concluir que la lucha de los movimientos latinoamericanos se halla anclada a la ilustración. Sea porque reivindican necesidades básicas, porque su principal interlocutor es el Estado, porque su contexto de lucha es atrasado o porque están atadas a localismos. En cualquiera de estos casos, se entiende que esos actores difícilmente pueden cuestionar los límites de la modernidad globalizada. En este artículo planteamos que tales conclusiones asumen un pensamiento dicotómico que diferencia y jerarquiza las dinámicas sociales según su mayor o menor distanciamiento de la tradición; una operación ilustrada que, paradójicamente, las teorías de movimientos deben a las perspectivas críticas de la ilustración; más específicamente, a su noción eurocéntrica de la modernidad. A partir de la revisión que de ese concepto ofrecen las posturas postcoloniales, concretamente el Programa de Investigación Modernidad/Colonialidad, dejamos sentadas algunas claves interpretativas que cambiarían los términos del debate sobre el escaso potencial de los movimientos latinoamericanos como actores críticos de la modernidad

Binary Evolution and the Progenitor of SN 1987A

Since the majority of massive stars are members of binary systems, an understanding of the intricacies of binary interactions is essential for understanding the large variety of supernova types and sub-types. I therefore briefly review the basic elements of binary evolution theory and discuss how binary interactions affect the presupernova structure of massive stars and the resulting supernovae. SN 1987A was a highly anomalous supernova, almost certainly because of a previous binary interaction. The most likely scenario at present is that the progenitor was a member of a massive close binary that experienced dynamical mass transfer during its second red-supergiant phase and merged completely with its companion as a consequence. This can naturally explain the three main anomalies of SN 1987A: the blue color of the progenitor, the chemical anomalies and the complex triple-ring nebula.Comment: Proceedings for the conference "SN 1987A: Ten Years After", eds. M. M. Phillips and N. B. Suntzeff, which took place in 1997, but which still has to appear in print. Proceedings are made public as a source of historical referenc

The Geometry of some Fibonacci Identities in the Hosoya Triangle

In this paper we explore some Fibonacci identities that are interpreted geometrically in the Hosoya triangle. Specifically we explore a generalization of the Cassini and Catalan identities from a geometric point of view. We also extend some properties present in the Pascal triangle to the Hosoya triangle.Comment: There are 16 figures representing Fibonacci identities in the Hosoya triangl

Teenage Childbearing in Latin American Countries

In spite of the rapid fertility transition experienced by most Latin American and Caribbean countries, teenage fertility has not changed at the same pace or in the same direction. Given that early childbearing is deleterious for both mother and child, we describe differentials in the levels and trends in teenage childbearing and analyze its proximate and socioeconomic determinants. We used Demographic and Health Surveys data from six LAC countries for which data are available for the second half of the 1990s: Bolivia, Brazil, Colombia, Guatemala, Dominican Republic and Peru. Teenage fertility trends indicate different patterns of change across countries by area of residence. However, in most countries teenage fertility has increased in rural areas but declined or remained constant in urban areas. Different contributions of marriage, proper use of family planning methods, and premarital births to teenage fertility behavior are reflected in differentials in unmarried parenthood across countries. Socioeconomic determinants are analyzed through simple logit model, multilevel analysis, and continuous-time hazard rate models. These analyses improve on prior research on LAC countries by including contextual/regional factors, isolating the effects into differentials in sexual activity and rates of childbearing, and by comparing the socioeconomic determinants of the timing of first birth and premarital birth. This research demonstrates that the effect of socioeconomic variables on the rate of childbearing can act through the timing of initial sexual intercourse (such as education, socioeconomic conditions of the households and area or residence) or through the timing of first birth (such as socialization in a female-headed family, availability - cceptability - use of family planning, and regional - country conditions, such as cultural and inherent characteristics).

Los movimientos sociales y la crisis del desarrollismo : Una aproximación teórica desde Latinoamérica

Ciertas teorías consideran que las acciones colectivas del Sur no pueden consolidarse en movimientos sociales porque sus contextos de lucha carecen de la condición moderna del desarrollo. Contra esta idea, este texto propone un abordaje teórico del desarrollo como un terreno de lucha fértil donde los movimientos latinoamericanos han retado los límites de la modernidad. Primero, se muestra que la crisis de la deuda externa de los años ochenta desembocó en la crisis del desarrollismo. Siguiendo la tesis de Escobar y Álvarez (1992), se argumenta que tal crisis contribuyó a la proliferación de movimientos en la región. Se señalan algunas claves de las perspectivas críticas del desarrollo que nutren esta tesis y luego, se explica por qué el dilema de esas perspectivas de optar excluyentemente por modelos de desarrollo alternativos o por alternativas a los modelos de desarrollo se torna insuficiente para comprender el impacto de las acciones colectivas contemporáneas. Finalmente, con base en las nociones de saber y lugar se apuntan desafíos para seguir pensando el nexo entre desarrollo, transformación y acción colectiva.De la década perdida en América Latina a la crisis del desarrollismo La década ganada: el desarrollo como campo de lucha de los movimientos de los ochenta Lecturas posmodernas/poscoloniales del desarrollo Lecturas posmodernas del desarrollo Lectura postcolonial del desarrollo Más allá del dilema entre el desarrollo alternativo y las alternativas al desarrollo Desafíos: el saber y el lugar como claves analíticas de los movimientos sociales Referencias Bibliográfica