Patterns of primary growth increments in otoliths of Sparus aurata larvae in relation to water temperature and food consumption

Sparus aurata larvae reared under controlled water-temperature conditions during the first 24 days after hatching displayed a linear relationship between age (t) and standard length (SL): SL = 2.68 + 0.19 t (r2 = 0.91l). Increments were laid down in the sagittae with daily periodicity starting on day of hatching. Standard length (SL) and sagittae radius (OR) were correlated: SL(mm) = 2.65 + 0.012 OR(mm). The series of measurements of daily growth increment widths (DWI), food density and water temperature were analyzed by means of time series analysis. The DWI series were strongly autocorrelated, the growth on any one day was dependent upon growth on the previous day. Time series of water temperatures showed, as expected, a random pattern of variation, while food consumed daily was a function of food consumed the two previous days. The DWI series and the food density were correlated positively at lags 1 and 2. The results provided evidence of the importance of food intake upon the sagittae growth when temperature is optimal (20ºC). Sagittae growth was correlated with growth on the previous day, so this should be taken into account when fish growth is derived from sagittae growth rates.

The Effects of Corruption and Seigniorage on Growth and Inflation

In the last two decades, cases of corruption have been unveiled in different countries, raising public awareness and reinforcing a trend in which society expects more from their leaders. Our objective in this paper is to examine the effects of corruption and seigniorage on inflation and growth rates. The model used in this article is an extension of the model used by Huang and Wei (2006). We find interesting results and one of them is that, under some conditions, corruption has a positive impact on the growth rate. JEL classification : D73, E52, E58, E62. Keywords : Corruption; Fiscal Policy; Growth; Monetary Policy; Seigniorage.

Investigating the impact of small versus large firms on economic performance of countries and industries

Following earlier work by Audretsch et al. (2002), we assume that an optimal size-class structure exists, in terms of achieving maximal economic growth rates. Such an optimal structure is likely to exist as economies need a balance between the core competences of large firms (such as exploitation of economies of scale) and those of smaller firms (such as flexibility and exploration of new ideas). Accordingly, changes in size-class structure (i.e., changes in the relative shares in economic activity accounted for by micro, small, medium-sized and large firms) may affect macro-economic growth. Using a unique data base of the EU-27 countries for the period 2002-2008 for five broad sectors of economic activity and four size-classes, we find empirical support which suggests that, on average for these countries over this period, the share of micro and large firms may have been ‘above optimum’ (particularly in lower income EU countries) whereas the share of medium-sized firms may have been ‘below optimum’ (particularly in higher income EU countries). This evidence suggests that the transition from a ‘managed’ to an ‘entrepreneurial’ economy (Audretsch and Thurik, 2001) has not been completed yet in all countries of the EU-27. Keywords: small firms, large firms, size-classes, macro-economic performance

Quantifying seasonality along a latitudinal gradient: from stream temperature to growth of invasive mosquitofish

Most ecosystems undergo substantial variation over the seasons, ranging from changes in abiotic features, such as temperature, light and precipitation, to changes in species abundance and composition. How seasonality varies along latitudinal gradients is not well known in freshwater ecosystems, despite being very important in predicting the effects of climate change and in helping to advance ecological understanding. Stream temperature is often well correlated with air temperature and influences many ecosystem features such as growth and metabolism of most aquatic organisms. We evaluated the degree of seasonality in ten river mouths along a latitudinal gradient for a set of variables, ranging from air and water temperatures, to physical and chemical properties of water and growth of an invasive fish species (eastern mosquitofish, Gambusia holbrooki ). Our results show that although most of the variation in air temperature was explained by latitude and season, this was not the case for water features, including temperature, in lowland Mediterranean streams, which depended less on season and much more on local factors. Similarly, although there was evidence of latitude-dependent seasonality in fish growth, the relationship was nonlinear and weak and the significant latitudinal differences in growth rates observed during winter were compensated later in the year and did not result in overall differences in size and growth. Our results suggest that although latitudinal differences in air temperature cascade through properties of freshwater ecosystems, local factors and complex interactions often override the water temperature variation with latitude and might therefore hinder projections of species distribution models and effects of climate change

A mixed splicing procedure for economic time series

This note develops a flexible methodology for splicing economic time series that avoids the extreme assumptions implicit in the procedures most commonly used in the literature. It allows the user to split the required correction to the older of the series being linked between its levels and growth rates on the basis what he knows or conjectures about the persistence of the factors that account for the discrepancy between the two series that emerges at their linking point. The time profile of the correction is derived from the assumption that the error in the older series reflects the inadequate coverage of emerging sectors or activities that grow faster than the aggregate.

Like milk or wine: Does firm performance improve with age?

Our empirical literature review shows that little is known about how firm performance changes with age, presumably because of the paucity of data on firm age. For Spanish manufacturing firms, we analyse the firm performance related to firm age between 1998 and 2006. We find evidence that firms improve with age, because ageing firms are observed to have steadily increasing levels of productivity, higher profits, larger size, lower debt ratios, and higher equity ratios. Furthermore, older firms are better able to convert sales growth into subsequent growth of profits and productivity. On the other hand, we also found evidence that firm performance deteriorates with age. Older firms have lower expected growth rates of sales, profits and productivity, they have lower profitability levels (when other variables such as size are controlled for), and also that they appear to be less capable to convert employment growth into growth of sales, profits and productivity.

Like milk or wine: Does firm performance improve with age?

Our empirical literature review shows that little is known about how firm performance changes with age, presumably because of the paucity of data on firm age. For Spanish manufacturing firms, we analyse the firm performance related to firm age between 1998 and 2006. We find evidence that firms improve with age, because ageing firms are observed to have steadily increasing levels of productivity, higher profits, larger size, lower debt ratios, and higher equity ratios. Furthermore, older firms are better able to convert sales growth into subsequent growth of profits and productivity. On the other hand, we also found evidence that firm performance deteriorates with age. Older firms have lower expected growth rates of sales, profits and productivity, they have lower profitability levels (when other variables such as size are controlled for), and also that they appear to be less capable to convert employment growth into growth of sales, profits and productivity. Keywords: firm age, firm growth, LAD, financial structure, vector autoregression JEL CODES: L25, L20

Ecological Footprint Inequality: A methodological review and some results

Scarcities of environmental services are no longer merely a remote hypothesis. Consequently, analysis of their inequalities between nations becomes of paramount importance for the achievement of sustainability in terms either of international policy, or of Universalist ethical principles of equity. This paper aims, on the one hand, at revising methodological aspects of the inequality measurement of certain environmental data and, on the other, at extending the scarce empirical evidence relating to the international distribution of Ecological Footprint (EF), by using a longer EF time series. Most of the techniques currently important in the literature are revised and then tested on EF data with interesting results. We look in depth at Lorenz dominance analyses and consider the underlying properties of different inequality indices. Those indices which fit best with environmental inequality measurements are CV2 and GE(2) because of their neutrality property, however a trade-off may occur when subgroup decompositions are performed. A weighting factor decomposition method is proposed in order to isolate weighting factor changes in inequality growth rates. Finally, the only non-ambiguous way of decomposing inequality by source is the natural decomposition of CV2, which additionally allows the interpretation of marginal term contributions. Empirically, this paper contributes to the environmental inequality measurement of EF: this inequality has been quite stable and its change over time is due to per capita vector changes rather than population changes. Almost the entirety of the EF inequality is explainable by differences in the means between the countries of the World Bank group. This finding suggests that international environmental agreements should be attempted on a regional basis in an attempt to achieve greater consensus between the parties involved. Additionally, source decomposition warns of the dangers of confining CO2 emissions reduction to crop-based energies because of the implications for basic needs satisfaction.

Ecological Footprint Inequality: A methodological review and some results

Scarcities of environmental services are no longer merely a remote hypothesis. Consequently, analysis of their inequalities between nations becomes of paramount importance for the achievement of sustainability in terms either of international policy, or of Universalist ethical principles of equity. This paper aims, on the one hand, at revising methodological aspects of the inequality measurement of certain environmental data and, on the other, at extending the scarce empirical evidence relating to the international distribution of Ecological Footprint (EF), by using a longer EF time series. Most of the techniques currently important in the literature are revised and then tested on EF data with interesting results. We look in depth at Lorenz dominance analyses and consider the underlying properties of different inequality indices. Those indices which fit best with environmental inequality measurements are CV2 and GE(2) because of their neutrality property, however a trade-off may occur when subgroup decompositions are performed. A weighting factor decomposition method is proposed in order to isolate weighting factor changes in inequality growth rates. Finally, the only non-ambiguous way of decomposing inequality by source is the natural decomposition of CV2, which additionally allows the interpretation of marginal term contributions. Empirically, this paper contributes to the environmental inequality measurement of EF: this inequality has been quite stable and its change over time is due to per capita vector changes rather than population changes. Almost the entirety of the EF inequality is explainable by differences in the means between the countries of the World Bank group. This finding suggests that international environmental agreements should be attempted on a regional basis in an attempt to achieve greater consensus between the parties involved. Additionally, source decomposition warns of the dangers of confining CO2 emissions reduction to crop-based energies because of the implications for basic needs satisfaction. Keywords: ecological footprint; ecological inequality measurement, inequality decomposition.

Cell size distribution in a random tessellation of space governed by the Kolmogorov-Johnson-Mehl-Avrami model: Grain size distribution in crystallization

The space subdivision in cells resulting from a process of random nucleation and growth is a subject of interest in many scientific fields. In this paper, we deduce the expected value and variance of these distributions while assuming that the space subdivision process is in accordance with the premises of the Kolmogorov-Johnson-Mehl-Avrami model. We have not imposed restrictions on the time dependency of nucleation and growth rates. We have also developed an approximate analytical cell size probability density function. Finally, we have applied our approach to the distributions resulting from solid phase crystallization under isochronal heating conditions

Biodiversity and global change in Mediterranean benthic communities: perspectives over large spatial and long temporal scales

Many terrestrial and marine systems are experiencing accelerating decline due to the effects of global change. This situation has raised concern about the consequences of biodiversity losses for ecosystem function, ecosystem service provision, and human well-being. Coastal marine habitats are a main focus of attention because they harbour a high biological diversity, are among the most productive systems of the world and present high anthropogenic interaction levels. The accelerating degradation of many terrestrial and marine systems highlights the urgent need to evaluate the consequence of biodiversity loss. Because marine biodiversity is a dynamic entity and this study was interested global change impacts, this study focused on benthic biodiversity trends over large spatial and long temporal scales. The main aim of this project was to investigate the current extent of biodiversity of the high diverse benthic coralligenous community in the Mediterranean Sea, detect its changes, and predict its future changes over broad spatial and long temporal scales. These marine communities are characterized by structural species with low growth rates and long life spans; therefore they are considered particularly sensitive to disturbances. For this purpose, this project analyzed permanent photographic plots over time at four locations in the NW Mediterranean Sea. The spatial scale of this study provided information on the level of species similarity between these locations, thus offering a solid background on the amount of large scale variability in coralligenous communities; whereas the temporal scale was fundamental to determine the natural variability in order to discriminate between changes observed due to natural factors and those related to the impact of disturbances (e.g. mass mortality events related to positive thermal temperatures, extreme catastrophic events). This study directly addressed the challenging task of analyzing quantitative biodiversity data of these high diverse marine benthic communities. Overall, the scientific knowledge gained with this research project will improve our understanding in the function of marine ecosystems and their trajectories related to global change.

Shocks and institutions in a job matching model

This paper explains the divergent behavior of European an US unemploymentrates using a job market matching model of the labor market with aninteraction between shocks an institutions. It shows that a reduction inTF growth rates, an increase in real interest rates, and an increase intax rates leads to a permanent increase in unemployment rates when thereplacement rates or initial tax rates are high, while no increase inunemployment occurs when institutions are "employment friendly". The paperalso shows that an increase in turbulence, modelle as an increase probabilityof skill loss, is not a robust explanation for the European unemploymentpuzzle in the context of a matching model with both endogenous job creationand job estruction.

Transitional effects of a pension system change in Spain

This paper studies the output effects, transition costs and the change in pension benefits derived from the substitution of the current unfunded pension system by a fully funded pension system financed through mandatory savings.These effects are estimated by using reduced versions of the neoclassical and endogenous growth frameworks. Because of the greater capital accumulation during the transition phase, final output increases by 23,6% (neoclassicalframework); and a 24,5-31,5% (endogenous growth framework). The initial revenue loss for the government would represent a 4,8% of the GDP, raising very slowly during the transition period. Given the new growth rates, rates of return ofphysical capital, and financial intermediation costs, we have that the capitalization pension benefits obtained by all 30-contribution-year worker would be more than twice than those that guarantee the financial sustainability of thepublic pension system

Transitional effects of a pension system change in Spain

This paper studies the output effects, transition costs and the change in pension benefits derived from the substitution of the current unfunded pension system by a fully funded pension system financed through mandatory savings.These effects are estimated by using reduced versions of the neoclassical and endogenous growth frameworks. Because of the greater capital accumulation during the transition phase, final output increases by 23,6% (neoclassicalframework); and a 24,5-31,5% (endogenous growth framework). The initial revenue loss for the government would represent a 4,8% of the GDP, raising very slowly during the transition period. Given the new growth rates, rates of return ofphysical capital, and financial intermediation costs, we have that the capitalization pension benefits obtained by all 30-contribution-year worker would be more than twice than those that guarantee the financial sustainability of thepublic pension system

The population dynamics of Halecium petrosum and Halecium pusillum (Hydrozoa, Cnidaria), epiphytes of Halimeda tuna in the nortwestern Mediterranean

Halecium petrosum and Halecium pusillum on the alga Halimeda tuna from Tossa de Mar, northeastern Spain, were studied. Asexual reproduction of H. petrosum, by stolonisation, occurred throughout the year except for July and August. Asexual reproduction of H. pusillum, by planktonic propagules, occurred throughout the year. Sexual reproduction was limited to the autumn in H. petrosum and spring in H. pusillum. The growth rates of colonies of both species were rapid but declined with increased size. Mean colony size over two consecutive two week periods increased approximately five-fold and three-fold for H. petrosum, and six-fold and four-fold for H. pusillum. Mortality was estimated to be high for both species, especially in summer. The maximum life span of colonies (ramets) of both species was estimated to be only eight weeks. Consequently most colonies do not reproduce sexually. The absence of reproduction of H. petrosum in summer, when the turnover of algal thalli was greatest, probably contributed to the summer decline in its abundance. In both species the genet (clone) survives for unknown, possibly very long, periods by asexual reproduction which facilites colonisation of other substrata.