Showing 1 - 10 of 255
This paper is concerned with selecting important covariates and estimating the index direction simultaneously for high dimensional single-index models. We develop an efficient Threshold Gradient Directed Regularization method via maximizing Distance Covariance (DC-TGDR) between the single index...
Persistent link: https://www.econbiz.de/10012433199
In this article, we study a nonparametric approach regarding a general nonlinear reduced form equation to achieve a better approximation of the optimal instrument. Accordingly, we propose the nonparametric additive instrumental variable estimator (NAIVE) with the adaptive group Lasso.We...
Persistent link: https://www.econbiz.de/10012433201
In additive models the problem of variable selection is strongly linked to the choice of the amount of smoothing used for components that represent metrical variables. Many software packages use separate toolsto solve the different tasks of variable selection and smoothing parameter choice. The...
Persistent link: https://www.econbiz.de/10010266175
A new regularization method for regression models is proposed. The criterion to be minimized contains a penalty term which explicitly links strength of penalization to the correlation between predictors. As the elastic net, the method encourages a grouping effect where strongly correlated...
Persistent link: https://www.econbiz.de/10010266210
Gene expression datasets usually have thousends of explanatory variables which are observed on only few samples. Generally most variables of a dataset have no effect and one is interested in eliminating these irrelevant variables. In order to obtain a subset of relevant variables an appropriate...
Persistent link: https://www.econbiz.de/10010266252
Specifying a prior distribution for the large number of parameters in the linear statistical model is a difficult step in the Bayesian approach to the design and analysis of experiments. Here we address this difficulty by proposing the use of functional priors and then by working out important...
Persistent link: https://www.econbiz.de/10009475773
We use the GRASP procedure to select a subset of financial ratios that are then used to estimate a model of logistic regression to anticipate financial distress on a sample of Spanish firms. The algorithm we suggest is designed "ad-hoc" for this type of variables. Reducing dimensionality has...
Persistent link: https://www.econbiz.de/10005737167
Persistent link: https://www.econbiz.de/10005596337
Persistent link: https://www.econbiz.de/10005602903
We represent the dynamic relation among variables in vector autoregressive (VAR) models as directed graphs. Based on these graphs, we identify so-called strongly connected components (SCCs). Using this graphical representation, we consider the problem of variable selection. We use the relations...
Persistent link: https://www.econbiz.de/10012099218