Poignard, Benjamin

写真a

Affiliation

Faculty of Science and Technology, Department of Mathematics ( Yagami )

Position

Associate Professor

Career 【 Display / hide

  • 2017.07
    -
    2019.03

    Japan Society for the Promotion of Science, Graduate School of Engineering Science, Osaka University

  • 2019.04
    -
    2023.03

    Osaka University, Graduate School of Economics

  • 2019.06
    -
    2023.03

    RIKEN AIP, High-dimensional statistical modeling unit

  • 2023.04
    -
    2025.03

    The University of Osaka, Graduate School of Economics

  • 2023.04
    -
    Present

    RIKEN AIP, Continuous optimization team, Visiting scientist

Academic Background 【 Display / hide

  • 2009.08
    -
    2014.09

    ESCP Europe, Master in Management (Grande Ecole Program)

    France

  • 2009.09
    -
    2011.06

    University Paris 1 Pantheon-Sorbonne, Bachelor and Master 1 in applied mathematics, 2009-2011

    France

  • 2011.09
    -
    2012.09

    University Paris 1 Pantheon-Sorbonne, Master Modeling and Mathematical Methods in Economics and Finance (DEA MMME)

    France

  • 2012.09
    -
    2014.09

    ENSAE Paris, Statistician-Economist (Grande Ecole Program)

    France

  • 2014.10
    -
    2017.06

    Center for Research in Economics and Statistics (CREST) and PSL University, PhD in applied mathematics

    France

 

Research Areas 【 Display / hide

  • Informatics / Statistical science (Asymptotic theory; Sparsity; Time series)

Research Keywords 【 Display / hide

  • Sparsity

  • Time series

  • Asymptotic theory

  • High-dimensional statistics

 

Papers 【 Display / hide

  • Model-based vs. agnostic methods for the prediction of time-varying covariance matrices

    Jean-David Fermanian, Benjamin Poignard, Panos Xidonas

    Annals of Operations Research (Springer Science and Business Media LLC)  346 ( 1 ) 511 - 548 2024.09

    Lead author, Last author, Corresponding author, Accepted,  ISSN  0254-5330

     View Summary

    This article is written in memory of Harry Markowitz, the founder of modern portfolio theory. We report a few human perspectives of his character, we review a large number of his contributions, published both in operations research and finance oriented journals, and we focus on one of the most critical, and still open, portfolio theory issues, the forecast of covariance matrices. Our contribution in this paper is placed exactly towards this direction. More specifically, we compare the performances of several approaches to predict the variance-covariance matrices of vectors of asset returns, through simulated and real data experiments: some dynamic models such as Dynamic Conditional Correlation (DCC) and C-vine GARCH on one side, and several agnostic methods (Average Oracle, usual “Sample” matrix) on the other side. The most robust methods seem to be DCC and the Average Oracle approaches.

  • Sparse M-estimators in semi-parametric copula models

    Jean-David Fermanian, Benjamin Poignard

    Bernoulli (Bernoulli Society for Mathematical Statistics and Probability)  30 ( 3 ) 2475 - 2500 2024.08

    Lead author, Last author, Corresponding author, Accepted,  ISSN  1350-7265

     View Summary

    We study the large-sample properties of sparse M-estimators in the presence of pseudo-observations. Our frame work covers a broad class of semi-parametric copula models, for which the marginal distributions are unknown and replaced by their empirical counterparts. It is well known that the latter modification significantly alters the limiting laws compared to usual M-estimation. We establish the consistency and the asymptotic normality of our sparsepenalized M-estimator and we prove the asymptotic oracle property with pseudo-observations, possibly in the case when the number of parameters is diverging. Our framework allows to manage copula-based loss functions that are potentially unbounded. Additionally, we state the weak limit of multivariate rank statistics for an arbitrary dimension and the weak convergence of empirical copula processes indexed by maps. We apply our inference method to Canonical Maximum Likelihood losses with Gaussian copulas, mixtures of copulas or conditional copulas. The theoretical results are illustrated by two numerical experiments.

  • Estimation of high-dimensional vector autoregression via sparse precision matrix

    Poignard B., Asai M.

    Econometrics Journal 26 ( 2 ) 307 - 326 2023.05

    Lead author, Last author, Corresponding author, Accepted,  ISSN  13684221

     View Summary

    We consider the problem of estimating sparse vector autoregression (VAR) via penalized precision matrices. This matrix is the output of the underlying directed acyclic graph of the VAR process, whose zero components correspond to the zero coefficients of the graphical representation of the VAR. The sparsity-based precision matrix estimator is deduced from the D-trace loss with convex and nonconvex penalty functions. We establish the consistency of the penalized estimator and provide the conditions for which all true zero entries of the precision matrix are actually estimated as zero with probability tending to one. The relevance of the method is supported by simulated experiments and a real data application.

  • High‐dimensional sparse multivariate stochastic volatility models

    Benjamin Poignard, Manabu Asai

    Journal of Time Series Analysis (Wiley)  44 ( 1 ) 4 - 22 2022.04

    Lead author, Last author, Corresponding author, Accepted,  ISSN  0143-9782

     View Summary

    Although multivariate stochastic volatility models usually produce more accurate forecasts compared with the MGARCH models, their estimation techniques such as Bayesian MCMC typically suffer from the curse of dimensionality. We propose a fast and efficient estimation approach for MSV based on a penalized OLS framework. Specifying the MSV model as a multivariate state-space model, we carry out a two-step penalized procedure. We provide the asymptotic properties of the two-step estimator and the oracle property of the first-step estimator when the number of parameters diverges. The performances of our method are illustrated through simulations and financial data. Supplementary Material presenting technical proofs is available online.

  • High-dimensional nonlinear feature selection with Hilbert-Schmidt Independence criterion Lasso

    Makoto Yamada, Benjamin Poignard, Hiroaki Yamada, Tobias Freidling

    Journal of the Japan Statistical Society  2022.04

    Lead author, Last author, Corresponding author, Accepted

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Statistical modelling for multivariate models of high dimension

    2025.04
    -
    2028.03

    若手研究, Principal investigator

Awards 【 Display / hide

  • Osaka University Prize, Young faculty

    2024, Osaka University

 

Courses Taught 【 Display / hide

  • STATISTICAL SCIENCE AND ITS EXERCISE

    2025

  • SEMINAR IN STATISTICAL SCIENCES

    2025

  • MATHEMATICS 2B

    2025

  • MATHEMATICAL STATISTICS 1 AND ITS EXERCISE

    2025

  • INDEPENDENT STUDY ON FUNDAMENTAL SCIENCE AND TECHNOLOGY

    2025

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Memberships in Academic Societies 【 Display / hide

  • The Japan Statistical Society, 

    2018.01
    -
    Present