965 resultados para Actively Managed
Resumo:
Author's pre-print
Resumo:
We use a new data set to study the determinants of the performance of open–end actively managed equity mutual funds in 27 countries. We find that mutual funds underperform the market overall. The results show important differences in the determinants of fund performance in the USA and elsewhere in the world. The US evidence of diminishing returns to scale is not a universal truth as the performance of funds located outside the USA and funds that invest overseas is not negatively affected by scale. Our findings suggest that the adverse scale effects in the USA are related to liquidity constraints faced by funds that, by virtue of their style, have to invest in small and domestic stocks. Country characteristics also explain fund performance. Funds located in countries with liquid stock markets and strong legal institutions display better performance.
Resumo:
Mediterranean landscapes comprise a complex mosaic of different habitats that vary in the diversity of their floral communities, pollinator communities and pollination services. Using the Greek Island of Lesvos as a model system, we assess the biodiversity value of six common habitats and measure ecosystemic 'health' using pollen grain deposition in three core flowering plants as a measure of pollination services. Three fire-driven habitats were assessed: freshly burnt areas, fully regenerated pine forests and intermediate age scrub; in addition we examined oak woodlands, actively managed olive groves and groves that had been abandoned from agriculture. Oak woodlands, pine forests and managed olive groves had the highest diversity of bees. The habitat characteristics responsible for structuring bee communities were: floral diversity, floral abundance, nectar energy availability and the variety of nectar resources present. Pollination services in two of our plant species, which were pollinated by a limited sub-set of the pollinator community, indicated that pollination levels were highest in the burnt and mature pine habitats. The third species, which was open to all flower visitors, indicated that oak woodlands had the highest levels of pollination from generalist species. Pollination was always more effective in managed olive groves than in abandoned groves. However, the two most common species of bee, the honeybee and a bumblebee, were not the primary pollinators within these habitats. We conclude that the three habitats of greatest overall value for plant-pollinator communities and provision of the healthiest pollination services are pine forests, oak woodland and managed olive groves. We indicate how the highest value habitats may be maintained in a complex landscape to safeguard and enhance pollination function within these habitats and potentially in adjoining agricultural areas. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
The natural resource base, terrestrial and marine, provides rural households in lower-income countries with income, food, shelter, and medicines, which are variously gathered and hunted in common lands and waters. These resources may be actively managed, whether by the government or local community; or may be de facto open access, with little effort by governments to prevent what may be de jure illegal extraction. This paper provides an appraisal of the literature that encompasses the direct value of wild resources to rural households; the extent to which these resources mitigate poverty and inequality; and the importance of the institutional context. The literature is increasingly addressing competing demands on the resource base both to support nearby livelihoods, and to enhance ecosystem services such as biodiversity; and how initiatives such as community-based payments for ecosystem services are changing how people interact with the resource base.
Resumo:
This study profiles innovators’ efforts to elevate student success initiatives from the current patchwork of support services to an actively managed enterprise process that is designed to systematically identify and rapidly intervene with students exhibiting behaviors predictive of attrition or graduation delays. Based on nearly two years of work and hundreds of interviews with colleges and universities across the country, the report presents 16 best practices in the areas most critical to improving student persistence and graduation.
Resumo:
Neste trabalho testa-se inicialmente se fundos com gestão ativa apresentam alfa (excesso de retorno) em relação aos índices de referência de fundos passivos. Simulações via bootstrap visam indicar se o excesso de retorno apresentado pode ser atribuído apenas à sorte. Com esta metodologia concluiu-se que a carteira agregada de fundos de investimentos de ação com gestão ativa no Brasil não apresenta excesso de retorno em relação aos principais índices da bolsa brasileira, quando líquidos de taxas e despesas. As simulações de bootstrap sugerem que uma quantidade maior de fundos apresenta retornos ajustados ao benchmark do que o esperado pelo efeito da aleatoriedade nos resultados.
Resumo:
Este trabalho realiza um teste empírico associando capital bancário e oferta de crédito livre no mercado brasileiro de 2003 a 2012. Em uma primeira etapa, propõem-se a estimativa do capital alvo, ativamente gerenciado pelos bancos de acordo com seu risco, características idiossincráticas e expectativas; e o cálculo do capital excedente a partir deste capital alvo. Na segunda etapa, investiga-se se este capital excedente e outros indicadores de capital associam-se com o crescimento do crédito livre. Os resultados indicam relação positiva, mas economicamente modesta (contrariando a premissa da alavancagem constante), entre o crescimento do crédito livre e o capital excedente. A relação é mais forte na segunda parte do período de análise, de setembro de 2008 a dezembro de 2012. O crescimento do crédito livre e os indicadores contábeis (Patrimônio Líquido sobre Ativo Total e índice de Basileia) apresentam relação positiva neste segundo período, também com efeitos econômicos modestos. Nos bancos públicos, não se encontrou relação significante entre o capital excedente – assim como entre os outros indicadores de capital – e o crescimento do crédito livre.
Resumo:
Este trabalho tem por objetivo identificar e quantificar o comportamento de manada (herd behavior) nos fundos de ações ativos do mercado financeiro brasileiro, valendo- se da medida LSV, proposta por Lakonishok et al (1992). Para tanto, analisamos a composição das carteiras de 642 fundos de ação, de 214 gestores diferentes, de setembro de 2007 até outubro de 2013. Em linha com a literatura relevante, há fortes evidências da ocorrência de efeito manada de forma heterogênea na amostra analisada. Encontramos indícios de que a intensidade do efeito manada varia de acordo com o tamanho do fundo e a capitalização da ação negociada.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
ESMA, the European watchdog of securities markets, has announced its intention to take a closer look at so-called ‘closet trackers’, with a view to identify whether there is a potential need for a coordinated pan-European policy response to these particular funds, which are supposedly actively managed but in reality closely track their benchmarks. In this commentary, Jean Pierre Casey suggests that more work needs to be done to demonstrate that a market failure exists. He also cautions on some of the difficulties associated with a potential regulatory intervention. In his view, the perceived problem is best tackled through transparency and competition.
Resumo:
Bark extracts of the African cherry (Prunus africana) are used to treat benign prostatic hyperplasia. This study examined the effects of commercial bark harvest on population dynamics in the Kilum-Ijim Forest Preserve on Mount Oku, Cameroon and on traditional uses. P. africana is valued for its timber and as fuel although its greatest value is as a traditional medicine for human and animal ailments. Harvest has depleted the resource and has eroded traditional forest protection practices. I constructed matrix models to examine the effects of bark harvest on population structure and on population dynamics in harvested and unharvested populations. Harvesting simulations examined the effect on the population growth rate (λ) with differing levels of mortality of harvest-sized and large trees and differing harvest frequencies. Size class frequencies for the entire forest decreased in a reverse j-shaped curve, indicating adequate recruitment in the absence of harvest. Individual plots showed differences from the overall forest data, suggesting effects of natural and man-made perturbations, particularly due to bark harvest. One plot (harvested in the 1980s) showed a temporal difference in λ and fluctuated around one, due to alternating high and low fruiting years; other unharvested plots showed smaller temporal differences. Harvested plots (harvested illegally in 1997) had values of λ less than one and showed small temporal differences. The control plot also showed λ less than one, due to poor recruitment in the closed canopy forest. The value of λ for the combined data was 0.9931 suggesting a slightly declining population. The elasticity matrix for the combined data indicated the population growth rate was most sensitive to the survival of the large reproductive trees (42.5% of the elasticity). In perturbation analyses, reducing the survival of the large trees caused the largest reductions in λ. Simulations involving harvesting frequency indicated λ returns to pre-harvest conditions if trees are re-harvested after 10–15 years, but only if the large trees are left unharvested. Management scenarios suggest harvest can be sustainable if seedlings and small saplings are planted in the forest and actively managed, although large-scale plantations may be the only feasible option to meet market demand. ^
Resumo:
Indigenous communities have actively managed their environments for millennia using a diversity of resource use and conservation strategies. Clam gardens, ancient rock-walled intertidal beach terraces, represent one example of an early mariculture technology that may have been used to improve food security and confer resilience to coupled human-ocean systems. We surveyed a coastal landscape for evidence of past resource use and management to gain insight into ancient resource stewardship practices on the central coast of British Columbia, Canada. We found that clam gardens are embedded within a diverse portfolio of resource use and management strategies and were likely one component of a larger, complex resource management system. We compared clam diversity, density, recruitment, and biomass in three clam gardens and three unmodified nonwalled beaches. Evidence suggests that butter clams (Saxidomus gigantea) had 1.96 times the biomass and 2.44 times the density in clam gardens relative to unmodified beaches. This was due to a reduction in beach slope and thus an increase in the optimal tidal range where clams grow and survive best. The most pronounced differences in butter clam density between nonwalled beaches and clam gardens were found at high tidal elevations at the top of the beach. Finally, clam recruits (0.5-2 mm in length) tended to be greater in clam gardens compared to nonwalled beaches and may be attributed to the addition of shell hash by ancient people, which remains on the landscape today. As part of a broader social-ecological system, clam garden sites were among several modifications made by humans that collectively may have conferred resilience to past communities by providing reliable and diverse access to food resources.
Resumo:
Objectives: There is a need for a more comprehensive understanding of how coaching processes psychologically operate. This paper presents the findings from a study aimed to characterise the coaching process experience and to identify how specific experiences contribute to coaching outcomes. Design: A qualitative design was adopted. Data was analysed by Interpretative Phenomenological Analysis (Smith, 2008). Method: Data was collected from 10 participants, this included coaches (N=4), coachees (N=5) and one commissioner, three times along the coaching process. A total of 30 interviews were undertaken. Findings: Coaching outcomes can be generated by three essential mechanisms: Projection of Future Self; Perspectivation of Present Self; and Confirmation of Past/Present Self. Each mechanism’s name represents a particular effect on coachee’s self and may evolve diverse coaching behaviours. Although they all can be actively managed to generate sustainability of outcomes, each mechanism tends to contribute differently to that sustainability. Conclusion: The study provides a comprehensive understanding of the different methodological and experiential ingredients of the coaching process and its implications. While most coaching research is focused on identifying coaching results based on a retrospective analysis, this is one of the first studies accompanying longitudinally the coaching process and capturing an integrative understanding of its dynamics. Moreover, the study provides evidence of how coaching can differently deliver sustainable outcomes and be used as a valuable developmental tool in organisations. The study contributes to our understanding of theory building and raises questions for further research on the uniqueness of coaching interventions.
Resumo:
This article presents a methodology for calculating the gains of an output feedback controller for active vibration control of flexible rotors. The methodology is based on modal reduction. The proportional and derivative gains are obtained by adjusting the first two damping factors of the system and keeping the lengths of the two eigenvalues constant in the real-imaginary plane. The methodology is applied to an industrial gas compressor supported by active tilting-pad journal bearings. The unbalance response functions and mode shapes of the flexible rotor with and without active control are presented, showing significative improvement in damping reserve with the control. The importance of sensor location is emphasized, on the basis of the energy necessary to operate the active system over the entire frequency range studied. The best results are obtained by a decentralized controller, observing displacement and velocity of the shaft at the bearing positions.