Recent macroeconomic performance in colombia: what went wrong?

Al finalizar la d�cada anterior la actividad real en Colombia experiment� la m�s aguda recesi�n de los �ltimos 50 a�os. Para explicar este fen�meno, postulamos un modelo VAR estructural no-triangular que describe la din�mica de la producci�n, los precios, el desempleo y los salarios durante las �ltimas dos d�cadas. La evidencia sugiere que, en el largo plazo, la pol�tica monetaria ha sido neutral con respecto al producto y la desempleo, mientras que la principal raz�n para el incremento de �ste �ltimo se explica por la forma en que se han determinado los salarios (formaci�n de expectativas hacia atr�s) y el incremento de los costos no salariales.structural VAR, unemployment, monetary policy, wages, nonwage labour costs, expectations

Forecasting Food Price Inflation in Developing Countries with Inflation Targeting Regimes: the Colombian Case

Many developing countries are adopting inflation targeting regimes to guide monetary policy decisions. In such countries the share of food in the consumption basket is high and policy makers often employ total inflation (as opposed to core inflation) to set inflationary targets. Therefore, central banks need to develop reliable models to forecast food inflation. Our literature review suggests that little has been done in the construction of models to forecast short-run food inflation in developing countries. We develop a model to improve short-run food inflation forecasts in Colombia. The model disaggregates food items according to economic theory and employs Flexible Least Squares given the presence of structural changes in the inflation series. We compare the performance of this new model to current models employed by the central bank. Next, we apply econometric methods to combine forecasts from alternative models and test whether such combination outperforms individual models. Our results indicate that forecasts can be improved by classifying food basket items according to unprocessed, processed and food away from home and by employing forecast combination techniques.Food Inflation, Time Series,

COINTEGRATION VECTOR ESTIMATION BY DOLS FOR A THREE-DIMENSIONAL PANEL

This paper extends the asymptotic results of the dynamic ordinary least squares (DOLS) cointegration vector estimator of Mark and Sul (2003) to a three-dimensional panel. We use a balanced panel of N and M lengths observed over T time periods. The cointegration vector is homogenous across individuals but we allow for individual heterogeneity using different short-run dynamics, individual-specific fixed effects and individual-specific time trends. Both individual effects are considered for the first two dimensions. This paper was motivated by the three-dimensional panel cointegration analysis used to estimate the total factor productivity for Colombian regions and sectors during 1975-2000 by Iregui, Melo and Ramírez (2007). They used the methodology proposed by Marrocu, Paci and Pala (2000); however, hypothesis testing is not valid under this technique. The methodology we are currently proposing allows us to estimate the long-run relationship and to construct asymptotically valid test statistics in the 3D-panel context.Cointegration, Dynamic OLS estimation, panel data in three dimensions. Classification JEL: C13; C33.

A Dynamic Factor Model for the Colombian Inflation

We use a dynamic factor model proposed by Stock and Watson [1998, 1999, 2002a,b] to forecast Colombian inflation. The model includes 92 monthly series observed over the period 1999:01-2008:06. The results show that for short-run horizons, factor model forecasts significantly outperformed the auto-regressive benchmark model in terms of the root mean squared forecast error statistic.Dynamic factor models, static factor models, forecast accuracy. Classification JEL: C13, C33, C53.

University Professors Education in The Use of ICT Venezuelan Public and Private Universities Case, (Carabobo U. and Metroplitana U)

La presente investigación indaga sobre la formación que dicen los docentes universitarios poseer en cuanto al uso y dominio de las Tecnologías de Información y Comunicación (TIC) para el apoyo de sus actividades académicas en el entorno educativo. Específicamente se abordó el tema, importancia de la formación de los docentes en instituciones públicas y privadas. La investigación es de tipo no experimental, descriptiva y de campo. Los resultados reflejan, en relación a la formación en TIC que dicen los docentes poseer para el uso y dominio en apoyo a las actividades académicas, es muy deficiente y en algunos casos nula.The present research investigate about the education that the university professor say have of the use and domain of ICT to support the academic activities in educational environments. Specifically we discuss the theme about the importance of the professor's education in public and private universities. The research is non experimental, descriptive and field type. The result show, in relation to the education in ICT that the professors said to have for the use and domain to support the academic activities was very low, and null in some cases

Influence of corrugation angle in the stirred yoghurt processing in plate heat exchangers

Research on heat transfer of non-Newtonian fluids during thermal processing is useful to optimise the heat exchanger design, as well as to define quality levels of the final product. In the present study, a nonisothermal and non-Newtonian flow in plate heat exchangers was simulated numerically, in order to evaluate the influence of corrugation angle on the thermal and hydrodynamics characteristics of yoghurt during cooling in a plate heat exchanger (PHE). Cooling treatment of stirred yoghurt is usually carried out in PHEs since these equipments are suitable for liquid-liquid heat transfer duties that require uniform and rapid cooling or heating. In this operation, two mechanisms of heat transfer occur: conduction, in the plates, and convection inside the channels. The set of equations that describe mathematically the problem were the Navier-Stokes equations, for incompressible and stationary flow, and Fourier’s law for the conduction problems. Additionally, a constitutive model that describes the rheological properties of yoghurt under the cooling conditions has to be established in order to define totally the problem. The used model was proposed by Afonso et al. (2003) and takes into account the influence of shear rate and temperatur

Sampling effort and information quality provided by rare and common species in estimating assemblage structure

Reliable biological assessments are essential to answer ecological and management questions but require well-designed studies and representative sample sizes. However, large sampling effort is rarely possible, because it demands large financial resources and time, restricting the number of sites sampled, the duration of the study and the sampling effort at each site. In this context, we need methods and protocols allowing cost-effective surveys that would, consequently, increase the knowledge about how biodiversity is distributed in space and time. Here, we assessed the minimal sampling effort required to correctly estimate the assemblage structure of stream insects sampled in near-pristine boreal and subtropical regions. We used five methods grouped into two different approaches. The first approach consisted of the removal of individuals 1) randomly or 2) based on a count threshold. The second approach consisted of simplification in terms of 1) sequential removal from rare to common species; 2) sequential removal from common to rare species; and 3) random species removal. The reliability of the methods was assessed using Procrustes analysis, which indicated the correlation between a reduced matrix (after removal of individuals or species) and the complete matrix. In many cases, we found a strong relationship between ordination patterns derived from presence/absence data (the extreme count threshold of a single individual) and those patterns derived from abundance data. Also, major multivariate patterns derived from the complete data matrices were retained even after the random removal of more than half of the individuals. Procrustes correlation was generally high ( > 0.8), even with the removal of 50% of the species. Removal of common species produced lower correlation than removal of rare species, indicating higher importance of the former to estimate resemblance between assemblages. Thus, we conclude that sampling designs can be optimized by reducing the sampling effort at a site. We recommend that such efforts saved should be redirected to increase the number of sites studied and the duration of the studies, which is essential to encompass larger spatial, temporal and environmental extents, and increase our knowledge of biodiversity.peerReviewe

Physical Geography of the Gulf of Guinea Oceanic Islands

The Gulf of Guinea, in the Atlantic coast of Central Africa, has three oceanic islands that arose as part of the Cameroon Volcanic Line. From northeast to southwest these are Príncipe (139 km2), São Tomé (857 km2), and Annobón (17 km2). Although relatively close to the adjacent mainland, the islands have distinct climactic and geomorphologic characteristics, and have remained isolated throughout their geological history. Consequently, they have developed a unique biodiversity, rich in endemic species. We provide an integrated overview of the physical setting of the islands, including their geographic location, geological origin, topography, geology and soils, climate zones, and prevailing wind and ocean currents—key features that underlie the evolution of their biodiversity