activity
20122023
most citedRobust Ranking of Happiness Outcomes: A Median Regression Perspective

3 citations · 11 across the 16 of their papers we have counts for

collaborators

16 papers

math.OC2023

Faster Stochastic Algorithms for Minimax Optimization under Polyak--Łojasiewicz Conditions

Lesi Chen, Boyuan Yao, Luo Luo

This paper considers stochastic first-order algorithms for minimax optimization under Polyak--Łojasiewicz (PL) conditions. We propose SPIDER-GDA for solving the finite-sum problem…

math.OC2023

Near-Optimal Nonconvex-Strongly-Convex Bilevel Optimization with Fully First-Order Oracles

Lesi Chen, Yaohua Ma, Jingzhao Zhang

In this work, we consider bilevel optimization when the lower-level problem is strongly convex. Recent works show that with a Hessian-vector product (HVP) oracle, one can provably…

math.OC2023

Communication Efficient Distributed Newton Method with Fast Convergence Rates

Chengchang Liu, Lesi Chen, Luo Luo +1

We propose a communication and computation efficient second-order method for distributed optimization. For each iteration, our method only requires communication c…

math.OC2023★ 2 cited

Faster Gradient-Free Algorithms for Nonsmooth Nonconvex Stochastic Optimization

Lesi Chen, Jing Xu, Luo Luo

We consider the optimization problem of the form , where the component is -mean-squared Lipschitz but…

math.OC2023

On Finding Small Hyper-Gradients in Bilevel Optimization: Hardness Results and Improved Analysis

Lesi Chen, Jing Xu, Jingzhao Zhang

Bilevel optimization reveals the inner structure of otherwise oblique optimization problems, such as hyperparameter tuning, neural architecture search, and meta-learning. A common…

cs.LG2022★ 2 cited

An Efficient Stochastic Algorithm for Decentralized Nonconvex-Strongly-Concave Minimax Optimization

Lesi Chen, Haishan Ye, Luo Luo

This paper studies the stochastic nonconvex-strongly-concave minimax optimization over a multi-agent network. We propose an efficient algorithm, called Decentralized Recursive grad…

cs.LG2022★ 1 cited

Near-Optimal Algorithms for Making the Gradient Small in Stochastic Minimax Optimization

Lesi Chen, Luo Luo

We study the problem of finding a near-stationary point for smooth minimax optimization. The recently proposed extra anchored gradient (EAG) methods achieve the optimal convergence…

stat.AP2021

Estimations of the Local Conditional Tail Average Treatment Effect

Le-Yu Chen, Yu-Min Yen

The conditional tail average treatment effect (CTATE) is defined as a difference between the conditional tail expectations of potential outcomes, which can capture heterogeneity an…

stat.ME2020

Sparse Quantile Regression

Le-Yu Chen, Sokbae Lee

We consider both -penalized and -constrained quantile regression estimators. For the -penalized estimator, we derive an exponential inequality on t…

econ.EM2019★ 3 cited

Robust Ranking of Happiness Outcomes: A Median Regression Perspective

Le-Yu Chen, Ekaterina Oparina, Nattavudh Powdthavee +1

Ordered probit and logit models have been frequently used to estimate the mean ranking of happiness outcomes (and other ordinal data) across groups. However, it has been recently h…

stat.ME2018★ 1 cited

High Dimensional Classification through -Penalized Empirical Risk Minimization

Le-Yu Chen, Sokbae Lee

We consider a high dimensional binary classification problem and construct a classification procedure by minimizing the empirical misclassification risk with a penalty on the numbe…

stat.CO2017

Exact computation of GMM estimators for instrumental variable quantile regression models

Le-Yu Chen, Sokbae Lee

We show that the generalized method of moments (GMM) estimation problem in instrumental variable quantile regression (IVQR) models can be equivalently formulated as a mixed integer…

stat.ME2016

Best Subset Binary Prediction

Le-Yu Chen, Sokbae Lee

We consider a variable selection problem for the prediction of binary outcomes. We study the best subset selection procedure by which the covariates are chosen by maximizing Manski…

stat.ME2015★ 2 cited

Breaking the curse of dimensionality in conditional moment inequalities for discrete choice models

Le-Yu Chen, Sokbae Lee

This paper studies inference of preference parameters in semiparametric discrete choice models when these parameters are not point-identified and the identified set is characterize…

stat.ME2013

Maximum Score Estimation of Preference Parameters for a Binary Choice Model under Uncertainty

Le-Yu Chen, Sokbae Lee, Myung Jae Sung

This paper develops maximum score estimation of preference parameters in the binary choice model under uncertainty in which the decision rule is affected by conditional expectation…

stat.ME2012

Testing Multiple Inequality Hypotheses : A Smoothed Indicator Approach

Le-Yu Chen, Jerzy Szroeter

This paper proposes a class of origin-smooth approximators of indicators underlying the sum-of-negative-part statistic for testing multiple inequalities. The need for simulation or…