Exact Limit of the Expected Periodogram in the Unit-Root case

We derive the limit of the expected periodogram in the unit-root case under general conditions. This function is seen to be independent of time, thus sharing a fundamental property with the stationary case equivalent. We discuss the consequences of this result to the frequency domain interpretation of filtered integrated time series.

Entrepreneurial Orientation as a main Resource and Capability on Small Firm’s Growth

This research provides a useful framework for identifying a small firms’ propensity to engage in entrepreneurial orientation. We examine the impact of the Entrepreneurial Orientation (EO) as a main resource and capability on small firm' growth. The growth seems to come out as an important demonstration of the entrepreneurial orientation of small firms (Davidsson, 1989; Green and Brown, 1997; Janney and Gregory, 2006). Thus, this research builds on prior conceptual research that suggests a positive integration between entrepreneurial orientation and resource-based view. In the first instance, the research will focus on reviewing literature in the emerging area of entrepreneurial orientation as it applies to growth oriented small firms and resource-based view of the firm. Secondly, an empirical study was developed based on a stratified sample of small firms of manufacturing industry. Data were submitted to a multivariate statistical analysis and a linear regression model was performed in order to predict the influence of the resources and capabilities on small firms' growth. In this sense, we consider the construct growth as a dependent variable and the ones relates with resources and capabilities (entrepreneur resources, firm resources, networks and EO) as independent variables. The research results suggest a set of resources and capabilities that promote the growth of the small firms. Also, the EO seems to have a predictive value on growth. Explaining variables related with resources and capabilities and EO were identified as essential in growth oriented small firms. It was still possible to conclude that the entrepreneurial firms which grew seem to have resources and develop more capabilities and take advantage in the search for those competences. This attitude reflects on the EO of the firm. This study has important implication for both researchers and practitioners. It highlights the necessity of firms to develop superior EO of all their members and also to invest on better resources and consequently superior capabilities as a way of reaching higher levels of growth. While previous authors have attempted to analyse certain aspects of this process (linkage between entrepreneurial orientation and growth), this research developed a framework that combines these and others factors (resource-based view) pertinent to growth oriented small firms. The results support the necessity to identify explicative variables of multiple levels to explain the growth of small firms. The adoption of an entrepreneurial orientation as an indispensable variable to the growth oriented small firms seems pertinent.Resources-Based View, Entrepreneurial orientation, Growth of Small Firms

Configuration of Logistics Activities across Life-Cycle of the Firms and Performance: Proposal of a Conceptual Model

In the last years, broad changes have contributed to the enhancement of the importance of the logistics as a source of competitive advantage, not just for increasing the satisfaction of the clients, but also for improving the performance of the firms. Nevertheless, the response functions of the firms to the referred changes are different according to the life-cycle stage that they face. The present paper aims to present a conceptual model that explores the connection between the life-cycle firm’s stages, and the standard profile of logistics activities, and the correspondent impact on performance.Life Cycle; Logistics; Performance

Exact Limit of the Expected Periodogram in the Unit-Root Case

We derive the limit of the expected periodogram in the unit-root case under general conditions. This function is seen to be time-independent, thus sharing a fundamental property with the stationary case equivalent. We discuss the consequences of this result to the frequency domain interpretation of filtered integrated time series.Periodogram, Unit root

A Multivariate Band-Pass Filter

We develop a multivariate filter which is an optimal (in the mean squared error sense) approximation to the ideal filter that isolates a specified range of fluctuations in a time series, e.g., business cycle fluctuations in macroeconomic time series. This requires knowledge of the true second-order moments of the data. Otherwise these can be estimated and we show empirically that the method still leads to relevant improvements of the extracted signal, especially in the endpoints of the sample. Our filter is an extension of the univariate filter developed by Christiano and Fitzgerald (2003). Specifically, we allow an arbitrary number of covariates to be employed in the estimation of the signal. We illustrate the application of the filter by constructing a business cycle indicator for the U.S. economy. The filter can additionally be used in any similar signal extraction problem demanding accurate real-time estimates.

A Multivariate Band-Pass Filter

We develop a multivariate filter which is an optimal (in the mean squared error sense) approximation to the ideal filter that isolates a specified range of fluctuations in a time series, e.g., business cycle fluctuations in macroeconomic time series. This requires knowledge of the true second-order moments of the data. Otherwise these can be estimated and we show empirically that the method still leads to relevant improvements of the extracted signal, especially in the endpoints of the sample. Our filter is an extension of the univariate filter developed by Christiano and Fitzgerald (2003). Specifically, we allow an arbitrary number of covariates to be employed in the estimation of the signal. We illustrate the application of the filter by constructing a business cycle indicator for the U.S. economy. The filter can additionally be used in any similar signal extraction problem demanding accurate real-time estimates.

ENTREPRENEURSHIP AND LIQUIDITY CONSTRAINTS IN DEPRIVED AREAS: EVIDENCE FROM THE SLUMS OF RIO DE JANEIRO

Several economic models have described the theoretical causes and onsequences of 'credit rationing' and 'under-investment'; one string of this literature shows the long-run effects of initial wealth distribution and entrepreneurial ability on the process of occupational choice and performance, and its consequences on inequality. Surprisingly, there is very little micro-level evidence on the existence and effects of 'credit rationing' in the context of developing countries. This is the contribution of the current paper. Using a survey of 4,553 entrepreneurs in 51 slums in Rio de Janeiro, this paper uses mean and quantile regression estimates to shows the effects of the type of initial capital, credit constraints, and human capital factors on entrepreneurs' performance. The main findings of the the paper are that entrepreneurs that were able to self-finance their business start-up presented earnings 16% greater than entrepreneurs that had to borrow their initial capital. In addition, entrepreneurs that explicitly claimed to be credit constrained performed substantially worse than their observationally identical counterparts, even if they were credit worthy. Both, initial source of funding and liquidity constraint presented greater effects on the highest quantiles. In terms of human capital, the current study shows positive and statistically significant returns for both years of schooling and experience, with higher returns on the lowest quantiles, indicating the potential role of these factors on inequality reduction.

Florestas, ambiente e sustentabilidade. Uma abordagem centrada nos serviços de ecossistema das florestas do distrito de Bragança

Os ecossistemas florestais do distrito de Bragança fornecem um conjunto notável de benefícios à sociedade. Neste trabalho são analisados os principais serviços de ecossistema florestal nesta região, adoptando a estrutura conceptual do Millenium Ecosystem Assessment. Descrevem-se resumidamente os serviços de suporte de biodiversidade, de produção de biomassa para energia, de produção de cogumelos e outros recursos não lenhosos, de regulação do CO2 atmosférico e do comportamento do fogo e ainda a biodiversidade enquanto património natural e cultural que as florestas encerram, bem como o bem-estar proporcionado pelos espaços verdes em ambiente urbanos. Debate-se no final a aplicação do conceito de serviço de ecossistema à prática e discutem-se alguns constrangimentos que a mesma apresenta no momento atual, nomeadamente em termos de valoração de serviços e do seu pagamento pela sociedade beneficiada

Utilização de princípios e métodos da ecologia da paisagem em ordenamento florestal

Portugal dispõe actualmente de condições para a implementação com sucesso de planos de ordenamento florestal concebidos a partir do conhecimento do funcionamento ecológico do território e por isso compatíveis com a conservação da natureza e da biodiversidade. A ecologia da paisagem ao dirigir-se ao estudo da estrutura, funcionamento e alteração de mosaicos heterogéneos do território e ao utilizar escalas de análise correspondentes às do ordenamento florestal previsto na lei portuguesa, constitui uma disciplina científica com naturais potencialidades de utilização neste âmbito. Existem princípios e procedimentos do âmbito da ecologia da paisagem que muito podem contribuir para a elaboração e implementação dos planos de ordenamento florestal em Portugal, alguns dos quais são apresentados neste texto