Research Group "Stochastic Algorithms and Nonparametric Statistics"

Research Seminar "Mathematical Statistics" Winter Semester 2024/25

16.10.2024 Botond Szabo (Bocconi Milan)
HVP 11 a, R.313 Privacy constrained semiparametric inference
For semi-parametric problems differential private estimators are typically constructed in a case-by-case basis. In this work we develop a privacy constrained semi-parametric plug-in approach, which can be used in general, over a collection of semi-parametric problems. We derive minimax lower and matching upper bounds for this approach and provide an adaptive procedure in case of irregular (atomic) functionals. Joint work with Lukas Steinberger (Vienna) and Thibault Randrianarisoa (Toronto, Vector Institute).
23.10.2024 Prof. Dr. Weining Wang (University of Groningen)
HVP 11 a, R.313 Conditional nonparametric variable screening by neural factor regression
High-dimensional covariates often admit linear factor structure. To effectively screen correlated covariates in high-dimension, we propose a conditional variable screening test based on non-parametric regression using neural networks due to their representation power. We ask the question whether individual covariates have additional contributions given the latent factors or more generally a set of variables. Our test statistics are based on the estimated partial derivative of the regression function of the candidate variable for screening and a observable proxy for the latent factors. Hence, our test reveals how much predictors contribute additionally to the non-parametric regression after accounting for the latent factors. Our derivative estimator is the convolution of a deep neural network regression estimator and a smoothing kernel. We demonstrate that when the neural network size diverges with the sample size, unlike estimating the regression function itself, it is necessary to smooth the partial derivative of the neural network estimator to recover the desired convergence rate for the derivative. Moreover, our screening test achieves asymptotic normality under the null after finely centering our test statistics that makes the biases negligible, as well as consistency for local alternatives under mild conditions. We demonstrate the performance of our test in a simulation study and two real world applications.
30.10.2024 Olga Klopp (ESSEC Business School, Paris)
HVP 11 a, R.313
06.11.2024
HVP 11 a, R.313
13.11.2024 Workshop: Foundations of Modern Nonparametric Statistics
Findet in Adlershof statt !!!
20.11.2024 Bernhard Stankewitz (Universität Potsdam)
HVP 11 a, R.313
27.11.2024 Julien Chhor (Toulouse School of Economics)
HVP 11 a, R.313
04.12.2024
HVP 11 a, R.313
11.12.2024
HVP 11 a, R.313
18.12.2024
HVP 11 a, R.313
08.01.2025

15.01.2025

22.01.2025

29.01.2024



last reviewed: October 8, 2024 by Christine Schneider