The Tenure Game: Building Up Academic Habits

Why do some academics continue to be productive after receiving tenure? This paper answers this question by using a Stackelberg differential game between departments and scholars. We show that departments can set tenure rules and standards as incentives for scholars to accumulate academic habits. As a result, academic habits have a lasting positive impact in scholar’s productivity, leading to higher scholar’s productivity rate of growth and higher productivity level.Role of economists; sociology of economics.

Does kin discrimination promote cooperation?

Funding: Natural Environment Research Council Independent Research Fellowship (Grant Number NE/K009524/1) and a European Research Council Consolidator grant no. (771387) (A.G.).Genetic relatedness is a key driver of the evolution of cooperation. One mechanism that may ensure social partners are genetically related is kin discrimination, in which individuals are able to distinguish kin from non-kin and adjust their behaviour accordingly. However, the impact of kin discrimination upon the overall level of cooperation remains obscure. Specifically, while kin discrimination allows an individual to help more-related social partners over less-related social partners, it is unclear whether and how the population average level of cooperation that is evolutionarily favoured should differ under kin discrimination versus indiscriminate social behaviour. Here, we perform a general mathematical analysis in order to assess whether, when and in which direction kin discrimination changes the average level of cooperation in an evolving population. We find that kin discrimination may increase, decrease or leave unchanged the average level of cooperation, depending upon whether the optimal level of cooperation is a convex, concave or linear function of genetic relatedness. We develop an extension of the classic ‘tragedy of the commons' model of cooperation in order to provide an illustration of these results. Our analysis provides a method to guide future research on the evolutionary consequences of kin discrimination.Publisher PDFPeer reviewe

Forecasting the equity risk premium with frequency-decomposed predictors

We show that the out-of-sample forecast of the equity risk premium can b e signi cantly improved by taking into account the frequency-domain relationship b etween the equity risk premium and several p otential predictors. We consider fteen predictors from the existing literature, for the out-of-sample forecasting p erio d from January 1990 to Decemb er 2014. The b est result achieved for individual predictors is a monthly out-of-sample R 2 of 2.98 % and utility gains of 549 basis p oints p er year for a mean-variance investor. This p erformance is improved even further when the individual forecasts from the frequency- decomp osed predictors are combined. These results are robust for di erent subsamples, including the Great Mo deration p erio d, the Great Financial Crisis p erio d and, more generically, p erio ds of bad, normal and go o d economic growth. The strong and robust p erformance of this metho d comes from its ability to disentangle the information aggregated in the original time series of each variable, which allows to isolate the frequencies of the predictors with the highest predictive p ower from the noisy parts.info:eu-repo/semantics/publishedVersio

Forecasting stock market returns by summing the frequency-decomposed parts

We forecast stock market returns by applying, within a Ferreira and Santa-Clara (2011) sum-of-the-parts framework, a frequency decomposition of several predictors of stock returns. The method delivers statistically and economically significant improvements over historical mean forecasts, with monthly out- of-sample R2 of 3.27% and annual utility gains of 403 basis points. The strong performance of this method comes from its ability to isolate the frequencies of the predictors with the highest predictive power from the noisy parts, and from the fact that the frequency-decomposed predictors carry complementary information that captures both the long-term trend and the higher frequency movements of stock market returns.info:eu-repo/semantics/publishedVersio

Dynamic Consumption and Portfolio Choice with Ambiguity about Stochastic Volatility

We introduce ambiguity about the variance of the risky asset's return in the model of Chacko and Viceira (2005) for dynamic consumption and portfolio choice with stochastic variance. We find that, with investors being able to update their portfolio continuously (as a function of the instantaneous variance), ambiguity has no impact. To shed some light on the case in which continuous portfolio updating is not possible, we also evaluate the effect of ambiguity when investors must use their expectation of future variance for their portfolio decision. In the latter scenario, demand for the risky asset can be decomposed into three components: myopic and intertemporal hedging demands (as in Chacko and Viceira (2005)) and ambiguity demand. Using long-run US data, Chacko and Viceira (2005) found that intertemporal hedging demand is empirically small, suggesting a low impact of stochastic variance on portfolio choice. Using the same calibration, we find that ambiguity demand may be very high, much more than intertemporal hedging demand. Therefore, stochastic variance can be very relevant for portfolio choice, not because of the variance risk, but because of investors' ambiguity about variance.Asset Allocation, Stochastic Volatility, Ambiguity

D. Carlos de Bragança, um Rei que se tornou pioneiro da Oceanografia em Portugal: Recursos para o ensino das ciências

O caso histórico de D Carlos de Bragança, Rei de Portugal de 1889 a 1908, um Oceanógrafo pioneiro, serve como ponto de partida para a exploração, tanto em contextos formais (ex. sala de aula) como não formais (ex. museu) de temas relacionados com a classificação biológica, métodos de colheita de espécimes e ilustração biológica (desenho por observação). As actividades propostas centram-se no trabalho do Rei D Carlos, que se dedicou ao estudo da fauna costeira Portuguesa, são dirigidas aos alunos de Biologia do Ensino Secundário e ajudam o aluno a desenvolver um conhecimento aprofundado acerca da natureza da ciência e dos métodos de pesquisa, promovendo também uma maior consciência acerca das complexas interacções que se estabelecem entre a ciência e a sociedade. Este conjunto de actividades inclui uma tarefa inicial, em sala de aula, de orientação para o tema, dois workshops desenvolvidos no Aquário Vasco da Gama e uma tarefa final, na sala de aula, de consolidação das aprendizagens. Nas tarefas de sala de aula, os estudantes analisam excertos de documentos históricos originais acerca do trabalho do Rei, com o objectivo de discutir e reflectir acerca da natureza da ciência. No Aquário, os estudantes participam activamente em actividades relacionadas com a classificação biológica e o desenho por observação. Todos os estudantes envolvidos (N=28) consideraram este projecto relevante para a aprendizagem das ciências, referindo não só a sua importância para a aquisição de conhecimentos, como para o aumento da compreensão acerca da natureza da ciência. Como consideração final, salientamos a importância do desenvolvimento de actividades baseadas na história da ciência como um veículo promotor da motivação e de uma efectiva aprendizagem das ciências, assim como para a promoção de uma parceria mais estreita entre as escolas e os museus de ciência

D. Carlos de Bragança, a pioneer of experimental marine oceanography: filling the gap between formal and informal science education

The activities presented in this paper are part of a wider project that investigates the effects of infusing the history of science in science teaching, toward students’ learning and attitude. Focused on the work of D. Carlos de Braganc¸a, King of Portugal from 1889 to 1908, and a pioneer oceanographer, the activities are addressed at the secondary Biology curriculum (grade 10, ages 15, 16). The proposed activities include a previsit orientation task, two workshops performed in a science museum and a follow-up learning task. In class, students have to analyse original historical excerpts of the king’s work, in order to discuss and reflect about the nature of science. In the museum, students actively participate in two workshops: biological classification and specimen drawing. All students considered the project relevant for science learning, stating that it was important not only for knowledge acquisition but also for the understanding of the nature of science. As a final remark we stress the importance of creating activities informed by the history of science as a foundation for improving motivation, sustaining effective science teaching and meaningful science learning, and as a vehicle to promote a closer partnership between schools and science museums

Preliminary study of the acoustic behavior concerning an innovative prototype for indoor modular partitioning

This paper presents a preliminary acoustic study concerning the development of the first prototype of a patented removable module for interior partitioning. It is a prefabricated, vertical element for division of interior spaces that does not require the use of gutters or technical support. A set of such modules, linearly disposed, will create a division, allowing the personalization of any indoor area, including open office spaces, rooms, among others. The main characteristic that distinguishes this element from the existing solutions available on the market is that its mobility relies exclusively on a set of integrated bearings at the base of each module. Through an incorporated elevation system, the user can lower the module, move it to the desired position and re-elevate it until pressed against the ledge of the ceiling, making it stable. In this sense, and taking into account its acoustic behavior, several tests were made in the LNEC acoustics lab. Airborne sound insulation tests for different typologies of the prototype were conducted, according to the applicable standards EN ISO 354:2003, EN ISO 717-1:2013 and EN ISO 10140-2:2010. Some important conclusions and analysis of the prototype viability were extracted