Knowledge misallocation and growth

We develop a growth model where knowledge is embodied in individuals and diffused across sectors through labor mobility. The existence of labor mobility costs constrains mobility and, thus, generates labor misallocation. Different levels of labor misallocation imply different levels of exploitation of available knowledge and, therefore, different total factor productivity across countries. We derive a positive relationship between growth and labor mobility, which is consistent with the empirical evidence, by assuming aggregate constant returns to capital. We also analyze the short and long run effects of labor mobility costs in the case of decreasing returns to capital. It turns out that changes in mobility costs have larger economic effects when different types of worker have small rather than large complementarities. Finally, we show that different labor income taxes or labor market tightness imply different rates of labor mobility and, therefore, can explain differences in Gross Domestic Product across countries.

The influence of substratum type and nutrient supply on biofilm organic matter utilization in streams

We investigated the effect of benthic substratum type (sand and rocks) and nutrient supply (N and P) on biofilm structure and heterotrophic metabolism in a field experiment in a forested Mediterranean stream (Fuirosos). Rock and sand colonization and biofilm formation was intensively studied for 44 d at two stream reaches: control and experimental (continuous addition of phosphate, ammonia, and nitrate). Structural (C, N, and polysaccharide content and bacterial and chlorophyll density) and metabolic biofilm parameters (b-glucosidase, peptidase, and phosphatase enzyme activities) were analyzed throughout the colonization process. The epilithic biofilm (grown on rocks) had a higher peptidase activity at the impacted reach, together with a higher algal and bacterial biomass. The positive relationship between the peptidase activity per cell and the N content of the epilithic biofilm suggested that heterotrophic utilization of proteinaceous compounds from within the biofilm was occurring. In contrast, nutrient addition caused the epipsammic biofilm (grown on sand) to exhibit lower b-glucosidase and phosphatase activities, without a significant increase in bacterial and algal biomass. The differential response to nutrient addition was related to different structural characteristics within each biofilm. The epipsammic biofilm had a constant and high C:N ratio (22.7) throughout the colonization. The epilithic biofilm had a higher C:N ratio at the beginning of the colonization (43.2) and evolved toward a more complex structure (high polysaccharide content and low C:N ratio) during later stages. The epipsammic biofilm was a site for the accumulation and degradation of organic matter: polysaccharides and organic phosphorus compounds had higher degradation activities

Informe d'Autors UOC a ISI Web of Knowledge. Març 2015

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Informe d'Autors UOC a ISI Web of Knowledge. Abril 2015

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Informe d'Autors UOC a ISI Web of Knowledge. Maig 2015

UOC

Coneixement lingüístic i matemàtic d'escolars de nivel sociocultural baix en programes d'immersió = Linguistic and mathematic knowledge in pupils of low sociocultural level in immersiom programmes

This piece of research compares knowledge of Catalan, Castilian and mathematics, as well as the attitudes to these two languages, of a sample of non-Catalan speaking pupils of low sociocultural level in their fourth year of primary school. Some of the pupils had followed an immersion programme in Catalan, whereas others had approached Catalan through their habitual language (Castilian). The findings show that not only did the immersion pupils obtain significantly better results in L2 (Catalan), but their mother tongue (Castilian) competence was undiminished and their performance on the mathematics test was superior to that of the other group. Moreover, the findings indicate that in pupils starting out from less favourable conditions (a low sociocultural level and a low I.Q.) the effect of the educational approach variable is greater than in other cases

Informe d'Autors UOC a ISI Web of Knowledge. Juny 2015

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