Browsing by Issue Date, starting with "2004-11"
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- Demand shocks and productivity growthPublication . Menezes, António Gomes deThis paper presents evidence on the relationship between cyclical shocks and productivity growth, for 20 2-digit SIC US manufacturing industries and a set of monetary policy, fiscal policy, and oil price shocks. The paper uses as a measure of productivity change a Solow residual corrected for a wide range of non-technological effects due to imperfect-competition, non-constant returns to scale, and cyclical utilization rates of capital and labor services. The empirical framework identifies policy shocks independently of productivity measurement issues via a two-step procedure. While the typical industry shows weak responses of productivity to the shocks considered, in some industries temporary contractionary policy shocks lead to increases in productivity. In addition, the results reveal that there are localized asymmetries, with contractionary policy shocks having larger produtivity effects than their expansionary counterparts. The results support the thesis that job reallocation is an important channel linking contractionary policy shocks and productivity growth. These results support the pit-stop view of downturns.
- Low-pay higher pay and job quality : empirical evidence for PortugalPublication . Vieira, José Cabral; Menezes, António Gomes de; Gabriel, PatríciaThis paper examines to what extent low pay jobs can be considered of low quality. For this purpose, we use three waves (1997-1999) of the European Community Household Panel (ECHP) for Portugal. The results indicate that low pay workers report a lower level of job satisfaction when compared with their higher paid counterparts. Moreover, some of the determinants of job satisfaction differ between these two types of workers. This supports the idea that low wage employment mainly comprises low quality jobs and is consistent with the segmented labour market theory, which claims the existence of good and bad jobs. This is, however, at odds with some empirical evidence recently reported for the British labour market where low pay individuals report a higher level of satisfaction, which is more in line with the notion that these workers obtain compensating differences in the form of non-pecuniary benefits.
- The connective tissue index of Helix aspersa as a metal biomarkerPublication . Amaral, André; Anselmo, Henrique; Cunha, Regina Tristão da; Rodrigues, ArmindoThe digestive gland of adult land snails, Helix aspersa, sampled from four different sites in São Miguel island (Azores) was submitted to chemical analyses, autometallography and haemalum/eosin staining, in order to quantify the relative abundance of heavy metals, calcium cells and connective tissue cells. Metals were visualized, through light microscopy, as black silver deposits mostly in the connective tissue cells. Metal levels, essentially of Cu and Fe, were related to the relative volumetric density of connective tissue cells but not to the relative volumetric density of calcium cells from the digestive gland epithelium. Thus, the connective tissue index presented herein is suggested as a biomarker of Cu exposure in terrestrial mollusks.
- On returns to training in PortugalPublication . Pereira, Pedro Telhado; Budría, SantiagoThis paper investigates the earnings effects of training in the Portuguese labour market. We use the Portuguese Labour Force Survey to classify training according to multiple criteria, including providing institution, purpose, duration, and content of the training activity. First, we establish some stylised facts about the extent and determinants of different types of training. We find that there are major differences in training participation across groups, with elder, low educated workers participating substantially less. Second, we measure the wage effects of training. We find that in Portugal returns to training are large and significant. The estimated coefficients are about 12% in the case of men and 37% in the case of women. We show that discriminating between gender, education level, experience, the public and the private sector, and industrial activity reveals important differences across categories of workers. Workers with low qualifications and long professional experience earn larger returns. On average, women receive larger returns than men, though they are subject to greater variation across education and experience groups. The average effect of training is similar in the private sector and in the public sector. Experience in the private sector and education in the public sector are key determinants of the returns to training. Further, training to improve current skills and training in a firm attract largest returns. Third, the paper investigates whether and to what extent training participation affects the probability of entering and leaving unemployment. We find that being trained does not affect significantly the transition probabilities.
- Determinantes da participação dos beneficiários no programa do Rendimento Mínimo Garantido no mercado de trabalhoPublication . Fortuna, Mário; Faria, Sandra Dias; Vieira, José Cabral; Menezes, António Gomes deWe present micro econometric evidence on the determinants of the probability that beneficiaries of the Minimum Guaranteed Income (MGI) participate in market production or in home production. We use a micro data set which covers all the beneficiaries of the MGI, up to 2001, for the Portuguese Region with the highest incidence of this program, namely, the Azores. We find striking diferences between women’s and men’s behaviour with respect to labour market participation decisions, with women heavily specialized in home production and men in market production. The probability of participating decreases with income support. Moreover, there are several aspects of household demographics that matter to female participation decisions. Therefore, policies designed to promote female labour supply should not be of the type one size fits all and must improve the terms of trade between home production and market production for women.
- On the effects of economic fluctuations on productivity growthPublication . Menezes, António Gomes deWe analyze the productivity effects of shocks to the real interest rate and to demand and supply conditions in a world where productivity enhancing activities are disruptive. The model predicts that temporary demand downturns may have positive productivity effects if the real interest rate is not too countercyclical, and that supply shocks do not affect productivity growth. The model is used to derive refined novel empirical tests on the so-called Opportunity Cost View of recessions (Aghion and Saint-Paul (1998)) vis a vis the competing theories of learning-by-doing and capital market imperfections.
- Contributos para o estudo da semântica de linguagens com concorrência e mobilidadePublication . Freire, Elisabete RaposoNeste trabalho mostra-se como abordagens matematicamente mais simples que as tradicionais podem ser usadas na definição da semântica de linguagens com concorrência e também de linguagens com mobilidade. Completam-se também alguns aspectos da semântica da mobilidade para os quais as propostas actualmente existentes apresentam limitações. Faz-se a exploração de dois tipos de técnicas para definir as semânticas operacionais e denotacionais de linguagens com concorrência e mobilidade. Por um lado usam-se os conjuntos com famílias de equivalência, um conceito mais simples e manejável, que parece substituir com vantagens ao nível da simplicidade os espaços métricos, usados nas abordagens tradicionais. Por outro lado, completa-se o trabalho com uma abordagem mais recente, baseada na utilização de coálgebras para definir sistemas e tirando partido das facilidades proporcionadas pelos conjuntos nominais na manipulação de nomes. A avaliação destas técnicas é feita sobre uma linguagem com sincronização restrita (Lsyn) e sobre uma linguagem com mobilidade (cálculo-π).