Search results for "Econometric"
showing 10 items of 3780 documents
Stochastic Nonlinear Time Series Forecasting Using Time-Delay Reservoir Computers: Performance and Universality
2014
International audience; Reservoir computing is a recently introduced machine learning paradigm that has already shown excellent performances in the processing of empirical data. We study a particular kind of reservoir computers called time-delay reservoirs that are constructed out of the sampling of the solution of a time-delay diFFerential equation and show their good performance in the forecasting of the conditional covariances associated to multivariate discrete-time nonlinear stochastic processes of VEC-GARCH type as well as in the prediction of factual daily market realized volatilities computed with intraday quotes, using as training input daily log-return series of moderate size. We …
So Many Variables: Joint Modeling in Community Ecology
2015
Technological advances have enabled a new class of multivariate models for ecology, with the potential now to specify a statistical model for abundances jointly across many taxa, to simultaneously explore interactions across taxa and the response of abundance to environmental variables. Joint models can be used for several purposes of interest to ecologists, including estimating patterns of residual correlation across taxa, ordination, multivariate inference about environmental effects and environment-by-trait interactions, accounting for missing predictors, and improving predictions in situations where one can leverage knowledge of some species to predict others. We demonstrate this by exa…
Option-Implied Volatility-Managed Asset Pricing Risk Factors and Resurrection of the Value Factor
2019
Option-implied volatility-managed risk factor models produce higher maximum squared Sharpe ratios than the recently proposed six-factor model, which is used as a benchmark model in this study. A model that incorporates option-implied volatility-managed risk factors based on dynamic scaling factors that systematically overestimate the expected market risk, as measured by the VIX, is superior to other asset pricing model specifications. After the death of the value factor has been repeatedly declared, it is surprising news that multivariate spanning regressions reveal that both the option-implied volatility-managed momentum and value factor are the only option-implied volatility-managed risk …
A discrete mathematical model for addictive buying: Predicting the affected population evolution
2011
This paper deals with the construction of a discrete mathematical model for addictive buying. Firstly, identifications of consumers buying behavior are performed by using multivariate statistical techniques based on real data bases and sociological approaches. Then the population is divided into appropriate groups according to the level of overbuying and a discrete compartmental model is constructed. The future short term addicted population is computed assuming several future economic scenarios. © 2010 Elsevier Ltd.
Algorithms for the inference of causality in dynamic processes: Application to cardiovascular and cerebrovascular variability
2015
This study faces the problem of causal inference in multivariate dynamic processes, with specific regard to the detection of instantaneous and time-lagged directed interactions. We point out the limitations of the traditional Granger causality analysis, showing that it leads to false detection of causality when instantaneous and time-lagged effects coexist in the process structure. Then, we propose an improved algorithm for causal inference that combines the Granger framework with the approach proposed by Pearl for the study of causality among multiple random variables. This new approach is compared with the traditional one in theoretical and simulated examples of interacting processes, sho…
Extended causal modeling to assess Partial Directed Coherence in multiple time series with significant instantaneous interactions.
2010
The Partial Directed Coherence (PDC) and its generalized formulation (gPDC) are popular tools for investigating, in the frequency domain, the concept of Granger causality among multivariate (MV) time series. PDC and gPDC are formalized in terms of the coefficients of an MV autoregressive (MVAR) model which describes only the lagged effects among the time series and forsakes instantaneous effects. However, instantaneous effects are known to affect linear parametric modeling, and are likely to occur in experimental time series. In this study, we investigate the impact on the assessment of frequency domain causality of excluding instantaneous effects from the model underlying PDC evaluation. M…
A fuzzy-set analysis of conditions influencing mutual fund performance
2019
Abstract This paper presents an application of fuzzy-set qualitative comparative analysis (fsQCA) to frame the conditions that lead to over- or under-performance of mutual funds. Building upon a considerable library of research on fund returns, the study uses fsQCA to affirm and extend earlier discoveries. Considered here is fund performance relative to Morningstar ratings, features of the funds themselves, as well as characteristics of the fund managers. Results suggest that positive Morningstar and analyst ratings are necessary conditions, on average, for funds to generate value according to the Jensen's alpha ratio. Just over seven percent of the cases imply that funds have attractive Sh…
Influences on mutual fund performance: comparing US and Europe using qualitative comparative analysis
2019
This study examines the conditions that lead mutual funds to underperform or outperform competitors. Using fuzzy-set qualitative comparative analysis (fsQCA), we draw upon extensive research on fund returns to affirm and extend earlier discoveries. Fund performance (Morningstar ratings), features of the funds themselves, and characteristics of the fund managers are considered. Positive Morningstar star and analyst ratings are necessary conditions for funds to generate value (measured by Jensen’s alpha). Funds with low management fees and low ongoing fees have attractive Sharpe ratios and high returns. Likewise, large funds with good Morningstar ratings have good Sharpe ratios and returns, o…
Modelos de crecimiento economico endogeno e historia economica: ¿Una nueva perspectiva ante el debate protección-librecambio?
1992
La evidencia cuantitativa aportada en los últimos años en diferentes investigaciones ha permitido una interpretación sobre la trayectoria económica española para el período 1874–1936, en la cual se combina la constatación de tasas apreciables de crecimiento con el mantenimiento de un grado elevado de atraso. Y como señaló Lluch (1988), si el ámbito temporal se amplía hasta la actualidad, cualquier interpretación debería incluir la tardía recuperación de este último como un hecho clave a considerar.No resulta, por tanto, sorprendente que las razones de la persistencia durante un largo período histórico de esta distancia entre los logros de la economía española y los conseguidos por los denom…
Tierras inundadas: El cultivo del arroz en la España contemporánea (1800-1936)
2002
Editada en la Fundación Empresa Pública El arroz fue una de las diversas dedicaciones agrícolas que permitieron mejorar los rendimientos en las condiciones particulares del mundo mediterráneo. Su implantación, sin embargo, exigió profundas transformaciones en el aprovechamiento del agua y comportó, a causa de las implicaciones sanitarias del cultivo, la intervención estatal. Su inserción en las estructuras agrarias existentes no fue, por tanto, fácil pero posibilitó el uso agrario de áreas de difícil aprovechamiento como la Albufera valenciana, el delta del Ebro y las Marismas del Guadalquivir. Desde la segunda mitad del siglo XIX, además, esta producción tuvo que adaptarse a la competencia…