38 research outputs found
Adaptive empirical Bayesian smoothing splines
In this paper we develop and study adaptive empirical Bayesian smoothing
splines. These are smoothing splines with both smoothing parameter and penalty
order determined via the empirical Bayes method from the marginal likelihood of
the model. The selected order and smoothing parameter are used to construct
adaptive credible sets with good frequentist coverage for the underlying
regression function. We use these credible sets as a proxy to show the superior
performance of adaptive empirical Bayesian smoothing splines compared to
frequentist smoothing splines
Uniformly Valid Inference Based on the Lasso in Linear Mixed Models
Linear mixed models (LMMs) are suitable for clustered data and are common in
e.g. biometrics, medicine, or small area estimation. It is of interest to
obtain valid inference after selecting a subset of available variables. We
construct confidence sets for the fixed effects in Gaussian LMMs that are
estimated via a Lasso-type penalization which allows quantifying the joint
uncertainty of both variable selection and estimation. To this end, we exploit
the properties of restricted maximum likelihood (REML) estimators to separate
the estimation of the regression coefficients and covariance parameters. We
derive an appropriate normalizing sequence to prove the uniform Cramer
consistency of the REML estimators. We then show that the resulting confidence
sets for the fixed effects are uniformly valid over the parameter space of both
the regression coefficients and the covariance parameters. Their superiority to
naive post-selection least-squares confidence sets is validated in simulations
and illustrated with a study of the acid neutralization capacity of U.S. lakes.Comment: 22 pages, 1 figur
On threshold estimation in threshold vector error correction models
Resource /Energy Economics and Policy,
Joint non-parametric estimation of mean and auto-covariances for Gaussian processes
Gaussian processes that can be decomposed into a smooth mean function and a stationary autocorrelated noise process are considered and a fully automatic nonparametric method to simultaneous estimation of mean and auto-covariance functions of such processes is developed. The proposed empirical Bayes approach is data-driven, numerically efficient, and allows for the construction of confidence sets for the mean function. Performance is demonstrated in simulations and real data analysis. The method is implemented in the R package eBsc