It's still 2%: evidence on convergence from 116 years of the US States panel data

A new debate over the speed of convergence in per capita income across economies is going on. Cross sectional estimates support the idea of slow convergence of about two percent per year. Panel data estimates support the idea of fast convergence of five, ten or even twenty percent per year. This paper shows that, if you ``do it right'', even the panel data estimation method yields the result of slow convergence of about two percent per year.

An assessment of empirical Bayes and composite estimators for small areas

We compare a set of empirical Bayes and composite estimators of the population means of the districts (small areas) of a country, and show that the natural modelling strategy of searching for a well fitting empirical Bayes model and using it for estimation of the area-level means can be inefficient.

Panel de expertos informe sobre los efectos económicos de diferentes medidas regulatorias dela pesquería de la anchoveta peruana

Presenta las regulaciones de la pesquería de la anchoveta para asegurar el mantenimiento de las capturas al/o cerca del nivel del rendimiento máximo sostenido y obtener la captura a un costo mínimo y utilizarla para obtener la máxima ganancia dentro de la estructura social, política y técnico económica de la industria.

Using composite estimators to improve both domain and total area estimation

In this article we propose using small area estimators to improve the estimatesof both the small and large area parameters. When the objective is to estimateparameters at both levels accurately, optimality is achieved by a mixed sampledesign of fixed and proportional allocations. In the mixed sample design, oncea sample size has been determined, one fraction of it is distributedproportionally among the different small areas while the rest is evenlydistributed among them. We use Monte Carlo simulations to assess theperformance of the direct estimator and two composite covariant-freesmall area estimators, for different sample sizes and different sampledistributions. Performance is measured in terms of Mean Squared Errors(MSE) of both small and large area parameters. It is found that the adoptionof small area composite estimators open the possibility of 1) reducingsample size when precision is given, or 2) improving precision for a givensample size.

Measuring and explaining farm inefficiency in a panel data set of mixed farms

This paper aims to estimate a translog stochastic frontier production function in the analysis of a panel of 150 mixed Catalan farms in the period 1989-1993, in order to attempt to measure and explain variation in technical inefficiency scores with a one-stage approach. The model uses gross value added as the output aggregate measure. Total employment, fixed capital, current assets, specific costs and overhead costs are introduced into the model as inputs. Stochasticfrontier estimates are compared with those obtained using a linear programming method using a two-stage approach. The specification of the translog stochastic frontier model appears as an appropriate representation of the data, technical change was rejected and the technical inefficiency effects were statistically significant. The mean technical efficiency in the period analyzed was estimated to be 64.0%. Farm inefficiency levels were found significantly at 5%level and positively correlated with the number of economic size units.

Forecasting and turning point predictions in a Bayesian panel VAR model

We provide methods for forecasting variables and predicting turning points in panel Bayesian VARs. We specify a flexible model which accounts for both interdependencies in the cross section and time variations in the parameters. Posterior distributions for the parameters are obtained for a particular type of diffuse, for Minnesota-type and for hierarchical priors. Formulas for multistep, multiunit point and average forecasts are provided. An application to the problem of forecasting the growth rate of output and of predicting turning points in the G-7 illustrates the approach. A comparison with alternative forecasting methods is also provided.

Impact of colonic cleansing on quality and diagnostic yield of colonoscopy: the European Panel of Appropriateness of Gastrointestinal Endoscopy European multicenter study.

BACKGROUND: The quality of colon cleansing is a major determinant of quality of colonoscopy. To our knowledge, the impact of bowel preparation on the quality of colonoscopy has not been assessed prospectively in a large multicenter study. Therefore, this study assessed the factors that determine colon-cleansing quality and the impact of cleansing quality on the technical performance and diagnostic yield of colonoscopy. METHODS: Twenty-one centers from 11 countries participated in this prospective observational study. Colon-cleansing quality was assessed on a 5-point scale and was categorized on 3 levels. The clinical indication for colonoscopy, diagnoses, and technical parameters related to colonoscopy were recorded. RESULTS: A total of 5832 patients were included in the study (48.7% men, mean age 57.6 [15.9] years). Cleansing quality was lower in elderly patients and in patients in the hospital. Procedures in poorly prepared patients were longer, more difficult, and more often incomplete. The detection of polyps of any size depended on cleansing quality: odds ratio (OR) 1.73: 95% confidence interval (CI)[1.28, 2.36] for intermediate-quality compared with low-quality preparation; and OR 1.46: 95% CI[1.11, 1.93] for high-quality compared with low-quality preparation. For polyps >10 mm in size, corresponding ORs were 1.0 for low-quality cleansing, OR 1.83: 95% CI[1.11, 3.05] for intermediate-quality cleansing, and OR 1.72: 95% CI[1.11, 2.67] for high-quality cleansing. Cancers were not detected less frequently in the case of poor preparation. CONCLUSIONS: Cleansing quality critically determines quality, difficulty, speed, and completeness of colonoscopy, and is lower in hospitalized patients and patients with higher levels of comorbid conditions. The proportion of patients who undergo polypectomy increases with higher cleansing quality, whereas colon cancer detection does not seem to critically depend on the quality of bowel preparation.

Causes of subcontracting: Evidence from panel data on construction firms

This paper examines factors explaining subcontracting decisions in the construction industry. Rather than the more common cross-sectional analyses, we use panel data to evaluate the influence of all relevant variables. We design and use a new index of the closeness to small numbers situations to estimate the extent of hold-up problems. Results show that as specificity grows, firms tend to subcontract less. The opposite happens when output heterogeneity and the use of intangible assets and capabilities increase. Neither temporary shortage of capacity nor geographical dispersion of activities seem to affect the extent of subcontracting. Finally, proxies for uncertainty do not show any clear effect.

Informe sobre la segunda reunión del panel de expertos de dinámica de población de la anchoveta peruana

La segunda reunión del panel de expertos continua sus estudios sobre recursos pesqueros tomando como tema principal la anchoveta peruana. Esta investigación considera el trabajo realizado el año anterior en su primera reunión.

Tercera sesión del panel de expertos sobre la dinámica de la población de anchoveta peruana, julio de 1972

La tercera sesión del panel de expertos hace un reencuentro de las condiciones oceanográficas entre el año 1971 y 1972 respecto a la pesquería de la anchoveta.

Informe de la Cuarta sesión del panel de expertos de la evaluación del stock de anchoveta peruana

Se presenta una revisión de los sucesos de las pesquerías en el lapso desde la anterior reunión del Panel en Julio, 1972 y de lo que se piensa ha tenido lugar en el recurso y en su medio ambiente; se indican diversas líneas de investigación del stock. Se resume la evidencia colateral acerca de los stocks y de su medio ambiente; ésta se relaciona con el fenómeno de El Niño, con las aves guaneras, el aumento de las capturas de sardinas, el contenido graso de la anchoveta y los estadios de maduración de la misma. Cada una de estas entidades indican que recientemente han prevalecido condiciones especiales en el ambiente de la anchoveta, en la biota asociada y en ciertos aspectos de su fisiología. Se ha hecho una detallada revisión de varios tipos de investigación de las poblaciones de anchoveta y de las evidencias que, acerca del estado del recurso, pueden derivarse de tales investigaciones. Se examinó la evidencia obtenida del uso de equipo acústico en el estudio de la distribución de stocks y en la estimación de su abundancia; el trabajo se realizó mediante exploraciones de varias embarcaciones (exploraciones Eureka) y de exploraciones especiales con el barco de investigación SNP-1; también se hizo uso de equipo eco-integrador. Se discuten las fuentes de errores sistemáticos existentes en ese trabajo. Se llega a la conclusión que lo que ese trabajo indicó fue que en Febrero de 1973 existía alrededor de 4 millones de toneladas de anchoveta.

Segundo panel de expertos:informe sobre los efectos económicos de diferentes medidas regulatorias de la pesquería de la Anchoveta peruana

En el informe de su cuarta reunión el Panel de Expertos en Dinámica revisó los datos proporcionados por el Instituto del Mar del Perú sobre el presente estado del stock de la anchoveta. Estos datos mostraron, evidentemente, que el stock de ancho veta se encontraba en una crítica situación a comienzos de 1973. Los mejores cálculos indicaban que la mayor captura que podría obtenerse en 1973 sería alrededor de a millones de toneladas pero que sería conveniente mantencrla muy por debajo de este nivel, especialmente antes de la mayor temporada de desove en Agosto-Setiembre. En 1974 el reclutamiento podía ser muy bajo especialmente si el stock desovante seguía siendo agotado por la pesca, de modo que las capturas en 1974 podrían ser mucho más bajas del promedio aún en el caso de que no hubiera restricciones para la pesca.

Informe de la primera sesión del panel internacional de expertos para evaluación de la población de la merluza peruana. Marzo 2003

Presentan los resultados del trabajo del panel siguiendo la secuencia establecida en los términos de referencia: estimar el estatus del stock de la merluza peruana, Proveer proyecciones del rendimiento y desarrollo del stock, bajo un escenario pesquero apropiado para el stock de la merluza peruana, comentar sobre medidas administrativas apropiadas de corto y mediano plazo, para la merluza peruana.