activity
20182026
most citedConfidence Regions Near Singular Information and Boundary Points With Applications to Mixed Models

5 citations · 5 across the 12 of their papers we have counts for

collaborators

13 papers

stat.ME2026

Score-based confidence intervals for variance-covariance parameters in linear mixed models

Matias Shedden, Karl Oskar Ekvall

We propose confidence intervals with near-nominal coverage of variance-covariance parameters in linear mixed models, even when interest or nuisance parameters are near the boundary…

math.ST2026

Asymptotics for likelihood ratio tests of boundary points with singular information and unidentifiable nuisance parameters

Karl Oskar Ekvall, Ola Hössjer, Matteo Bottai +1

We establish the asymptotic distribution of likelihood ratio tests when nuisance parameters are unidentifiable under the null hypothesis, parameters of interest lie on the boundary…

stat.ME2025

Universal inference for variance components

Yiqiao Zhang, Karl Oskar Ekvall, Aaron J. Molstad

We consider universal inference in variance components models, focusing on settings where the parameter is near or at the boundary of the parameter set. Two cases, which are not ha…

math.ST2025

Uniform inference in linear mixed models

Karl Oskar Ekvall, Matteo Bottai

We provide finite-sample distribution approximations, that are uniform in the parameter, for inference in linear mixed models. Focus is on variances and covariances of random effec…

stat.ME2024

Fast and reliable confidence intervals for a variance component

Yiqiao Zhang, Karl Oskar Ekvall, Aaron J. Molstad

We show that confidence intervals in a variance component model, with asymptotically correct uniform coverage probability, can be obtained by inverting certain test-statistics base…

stat.ME2022

Direct covariance matrix estimation with compositional data

Aaron J. Molstad, Karl Oskar Ekvall, Piotr M. Suder

Compositional data arise in many areas of research in the natural and biomedical sciences. One prominent example is in the study of the human gut microbiome, where one can measure…

stat.ME2022

Concave likelihood-based regression with finite-support response variables

Karl Oskar Ekvall, Matteo Bottai

We propose a unified framework for likelihood-based regression modeling when the response variable has finite support. Our work is motivated by the fact that, in practice, observed…

math.ST2021★ 5 cited

Confidence Regions Near Singular Information and Boundary Points With Applications to Mixed Models

Karl Oskar Ekvall, Matteo Bottai

We propose confidence regions with asymptotically correct uniform coverage probability of parameters whose Fisher information matrix can be singular at important points of the para…

stat.ME2021

Mixed-type multivariate response regression with covariance estimation

Karl Oskar Ekvall, Aaron J. Molstad

We propose a new method for multivariate response regression and covariance estimation when elements of the response vector are of mixed types, for example some continuous and some…

stat.ME2020

Targeted Principal Components Regression

Karl Oskar Ekvall

We propose a principal components regression method based on maximizing a joint pseudo-likelihood for responses and predictors. Our method uses both responses and predictors to sel…

math.ST2019

Convergence Analysis of a Collapsed Gibbs Sampler for Bayesian Vector Autoregressions

Karl Oskar Ekvall, Galin L. Jones

We study the convergence properties of a collapsed Gibbs sampler for Bayesian vector autoregressions with predictors, or exogenous variables. The Markov chain generated by our algo…

math.ST2018

Consistent Maximum Likelihood Estimation Using Subsets with Applications to Multivariate Mixed Models

Karl Oskar Ekvall, Galin L. Jones

We present new results for consistency of maximum likelihood estimators with a focus on multivariate mixed models. Our theory builds on the idea of using subsets of the full data t…

stat.CO2018

Likelihood-Based Inference with Separable Correlation Matrices

Karl Oskar Ekvall

This paper proposes methods for likelihood-based inference in multivariate linear regressions when the correlation matrix of the responses is separable; that is, it has a Kronecker…