Explaining momentum profits with an epidemic diffusion model

We show that information diffusion is a function of its dissemination and assimilation. Whereas dissemniation is a function of observable factors such as volume and price volatility, assimilation is dependent on unobservable factors such as the usefulness and reliability of information. We find that buying low volume (or low volatility) past losers and shortselling low volume (or low volatility) past winners generates a positive net return across the entire sample period and especially during bear markets. Second, buying high volatility past winners and shortselling high volatility past losers generates a positive net return, especially during bear markets.     

Socioeconomic predictors of forest use values in the Peruvian Amazon: A potential tool for biodiversity conservation

Conservation is a crisis discipline requiring rapid action with limited funds. This study examines the potential of socioeconomic variables to predict forest use values. If natural resource use can be predicted from socioeconomic data, conservation planners could rapidly identify and focus conservation programs on the sectors of local populations that most intensively utilize local flora and fauna. Families in three communities in the northern Peruvian Amazon were surveyed over a 6-month period. Data were collected on use of flora and fauna from six locally determined use categories (food, medicine and poisons, wood, weavings, adornments, and “other”) in forest types of three age classes (fallow fields—very young forests, young secondary forests, and old secondary forests). Forest use values were the dependant variables calculated in $/ha/year. Socioeconomic variables included: age, education, family size, residence time, land worked, land owned, number of fishing nets, chickens, pigs, cows, and/or mules owned (all proxies for productive assets), and level of ecological knowledge (ability of informants to correctly identify forest species and answer basic questions about their biology). Ordinary least square multiple regressions were run independently for each forest type. Regressions were also run separately for the two most valuable use categories, food and wood. Low R² adjusted values (all < 0.3) reflect the difficulty in predicting human behavior due to confounding variables and complex interactions. Residence time and a household's community of residence were the most significant predictors of forest use values. Households in Vista Alegre, the community with the highest density of people and smallest landholdings per household, extracted the highest value of forest products per hectare. The longer a family stayed in any community the higher the value of forest goods they extracted. If families that lived in an area longest are the most intensive extractors of forest products, they should be a major focus for conservation programming. In addition, the higher value of products extracted from forests by some families may make them more open to strategies seeking to protect long-term viability of the resources they utilize. The importance of residence time also indicates that planners need to account for changes in the resource use patterns of stakeholders over time.     

Pseudo empirical likelihood method in the presence of missing data

In this paper, we propose an estimator for the population mean when some observations on the study and auxiliary variables are missing from the sample. The proposed estimator is valid for any unequal probability sampling design, and is based upon the pseudo empirical likelihood method. The proposed estimator is compared with other estimators in a simulation study.     

Governance structures in R&D networks: An analysis in the European context

This paper analyses governance structures used to organize partnerships in R&D networks using two approaches: transaction costs theory and social capital theory. We argue that these theories are complementary; this explains forms of governance through the degrees of administrative (structural and safeguard mechanism) and social factors (cohesion and openness) they embody. Data was obtained from European R&D networks created through Framework Programmes which include a great number of universities, non profit institutions and firms. Findings show the variables that characterize and explain the governance forms based on the applicability of R&D networks. This study not only provides a theoretical model for analysing governance structures of these networks, but is also useful for both improving the management of networks and for fostering collaboration at an international level.     

Combining biodiversity modeling with political and economic development scenarios for 25 EU countries

In the EURURALIS project, a chain of models was used to predict the changes in sustainable development indicators for European human well-being, ecology and economy issues, for four alternative scenarios of the future socio-economic development. This paper describes the biodiversity analysis of the project. Models based on general relationships between environmental factors and biodiversity loss were combined with socio-economic, land-use and environmental models to derive data that were integrated into an interactive tool for policy makers. The biodiversity analysis takes into account the effects of land-use change, climate change, fragmentation by major roads, area of unfragmented patches, nitrogen deposition, forestry and disturbance. Results show that biodiversity is projected to decrease between now and 2030 in most countries for all scenarios, indicating that it is unlikely that the EU will be able to fulfill its commitment to stop biodiversity loss by 2010. This is mainly due to urbanization and increase in stress factors, and outweighs the area increase of nature arising from land abandonment. Merits, limitations and uncertainties of this approach to biodiversity assessment are discussed.     

Financial liberalization,financial sector development and growth: Evidence from Malaysia

The objective of this paper is to examine whether financial development leads to economic growth or vice versa in the small open economy of Malaysia. Using time series data from 1960 to 2001, we conduct cointegration and causality tests to assess the finance-growth link by taking the real interest rate and financial repression into account. The empirical evidence suggests that financial liberalization, through removing the repressionist policies, has a favorable effect in stimulating financial sector development. Financial depth and economic development are positively related; but contrary to the conventional findings, our results support Robinson's view that output growth leads to higher financial depth in the long-run.     

Modelling of repairable systems with various degrees of repair

The availability of a stochastic repairable system depends on the failure behaviour and on repair strategies. In this paper, we deal with a general repair model for a system using auxiliary counting processes and corresponding intensities which include various degrees of repair (between minimal repair and perfect repair). For determining the model parameters we need estimators depending on failure times and repair times: maximum likelihood (ML) estimator and Bayes estimators are considered. Special results are obtained by the use of Weibull-type intensities and random observation times.