Understanding productivity dynamics: A task taxonomy approach

As job markets have been polarizing, firms have been changing their labor inputs. By using matched employer–employee data for Portugal, we examine whether labor market polarization has occurred within or across firms and how labor input upgrades have contributed to overall productivity growth. We develop a firm taxonomy based on worker's occupational data. Firms can be focused on one task – Abstract, Manual or Routine – on a combination of tasks, or none. Results show that Abstract firms are the most productive and their share has increased over time. Manual firms, the least productive, have had a stable share throughout the period. Routine firms have seen their share decline over time. The dynamic decomposition of the estimated productivity reveals that productivity growth is propelled by increased market shares of the most productive incumbents and exiting of the least productive, especially for Abstract firms. Notwithstanding these productivity growth drivers, they fail to avert the productivity stagnation observed in Portugal between 2004 and 2009 due to the overall decline in productivity of incumbent firms, especially Routine. We discuss the policy implications of our results which are relevant to other European economies also lagging behind in terms of knowledge and innovation capabilities.     

Establishment of higher education institutions and new firm entry

The presence of universities has generally been associated with technological entrepreneurship. But what is the real impact of new universities on the levels of firm creation in a region? The present paper uses policy evaluation methodologies and longitudinal data on the establishment of higher education institutions in Portuguese municipalities for the period 1992-2002 to examine its effect on entry rates of new firms in different sectors. We find that the establishment of a new university has a positive and significant effect on subsequent levels of knowledge based firm entry in municipalities, and a negative effect on the levels of entry in other sectors, such as low-tech manufacturing.     

Un estudio sobre la comprensión de términos espacio-temporales en niños de 4 a 6 años

Resumen

Este estudio trató de comprobar si la comprensión de los pares de palabras «antesldespués», «delanteldetrás» y «primerolúltimo» presenta relación con el significado dominante en la comunidad lingüistica, la complejidad de la tarea, la asimetría de los términos y la edad. Se utilizaron 90 adultos y 180 niños entre 4 y 6 años. Los adultos definieron las palabras a analizar; loi niños ejecutaron las consignas en tres contextos: espacial, espacio-temporal y temporal. Los resultados indican que el par «antesldespués» es comprendido más pronto en el sentido temporal, el par «delanteldetrás» en sentido espacial. Estos datos coinciden con los obtenidos en las definiciones adultas. «Primeroúltimo» es mejor comprendido en tareas temporales, aunque los adultos dieron definiciones ambiguas. Por otra parte, la compejidad de la tarea parece influir en la comprensión: l'a ausencia de rasgos de los objetos y. el. orden gramatical inverso dificultan la tarea. Estos resultados sugieren que la hipótesis de los rasgos sonánticos es insuficiente para explicar la adquisición del signifcado.     

Concept or computation: Students' understanding of the mean

In statistics, and in everyday life as well, the arithmetic mean is a frequently used average. The present study reports data from interviews in which students attempted to solve problems involving the appropriate weighting and combining of means into an overall mean. While mathematically unsophisticated college students can easily compute the mean of a group of numbers, our results indicate that a surprisingly large proportion of them do not understand the concept of the weighted mean. When asked to calculate the overall mean, most subjects answered with the simple, or unweighted, mean of the two means given in the problem, even though these two means were from different-sized groups of scores. For many subjects, computing the simple mean was not merely the easiest or most obvious way to initially attack the problem; it was the only method they had available. Most did not seem to consider why the simple mean might or might not be the correct response, nor did they have any feeling for what their results represented. For many students, dealing with the mean is a computational rather than a conceptual act. Knowledge of the mean seems to begin and end with an impoverished computational formula. The pedagogical message is clear: Learning a computational formula is a poor substitute for gaining an understanding of the basic underlying concept.Research support: Research reported in this paper was supported by NSF research award No. SED78-22043 in the Joint National Institute of Education-National Science Foundation Program of Research on Cognitive Processes and the Structure of Knowledge in Science and Mathematics.     

Development and evaluation of a Portuguese early literacy programme / Desarrollo y evaluación de un programa portugués de alfabetización temprana

Abstract

Over the last three decades, research in this field has addressed different early literacy skills and studied the pedagogical practices that promote the initial learning of reading and writing skills. This study develops a programme that promotes early literacy skills, called Ouvir as Letras (Listen to the Letters). The efficacy of the programme was evaluated in comparison with two implementations of the Portuguese preschool education curriculum: one structured and the other semi-structured, in a quasi-experimental design with a pre-test, post-test and follow-up. The study was carried out with the participation of 124 five- and six-year-old children who attended preschool in four schools in the north of Portugal. The results suggest that the Ouvir as Letras programme was more effective in facilitating the acquisition of basic skills to initiate children in the learning of written language.