principal component regression
Errors-in-variables Fréchet Regression with Low-rank Covariate Approximation
Fréchet regression has emerged as a promising approach for regression analysis involving non-Euclidean response variables. However, its practical applicability has been hindered by its reliance on ideal scenarios with abundant and noiseless covariate data. In this paper, we present a novel estimation method that tackles these limitations by leveraging the low-rank structure inherent in the covariate matrix. Our proposed framework combines the concepts of global Fréchet regression and principal component regression, aiming to improve the efficiency and accuracy of the regression estimator. By incorporating the low-rank structure, our method enables more effective modeling and estimation, particularly in high-dimensional and errors-in-variables regression settings. We provide a theoretical analysis of the proposed estimator's large-sample properties, including a comprehensive rate analysis of bias, variance, and additional variations due to measurement errors. Furthermore, our numerical experiments provide empirical evidence that supports the theoretical findings, demonstrating the superior performance of our approach. Overall, this work introduces a promising framework for regression analysis of non-Euclidean variables, effectively addressing the challenges associated with limited and noisy covariate data, with potential applications in diverse fields.
On the number of variables to use in principal component regression
We study least squares linear regression over $N$ uncorrelated Gaussian features that are selected in order of decreasing variance. When the number of selected features $p$ is at most the sample size $n$, the estimator under consideration coincides with the principal component regression estimator; when $p> n$, the estimator is the least $\ell_2$ norm solution over the selected features.
On Robustness of Principal Component Regression
Consider the setting of Linear Regression where the observed response variables, in expectation, are linear functions of the p-dimensional covariates. Then to achieve vanishing prediction error, the number of required samples scales faster than pσ2, where σ2 is a bound on the noise variance. In a high-dimensional setting where p is large but the covariates admit a low-dimensional representation (say r p), then Principal Component Regression (PCR), cf.
A PLS-Integrated LASSO Method with Application in Index Tracking
Tang, Shiqin, Dong, Yining, Qin, S. Joe
In traditional multivariate data analysis, dimension reduction and regression have been treated as distinct endeavors. Established techniques such as principal component regression (PCR) and partial least squares (PLS) regression traditionally compute latent components as intermediary steps -- although with different underlying criteria -- before proceeding with the regression analysis. In this paper, we introduce an innovative regression methodology named PLS-integrated Lasso (PLS-Lasso) that integrates the concept of dimension reduction directly into the regression process. We present two distinct formulations for PLS-Lasso, denoted as PLS-Lasso-v1 and PLS-Lasso-v2, along with clear and effective algorithms that ensure convergence to global optima. PLS-Lasso-v1 and PLS-Lasso-v2 are compared with Lasso on the task of financial index tracking and show promising results.
Calibrated Principal Component Regression
Wu, Yixuan Florence, Zhu, Yilun, Cao, Lei, Shi, Naichen
We propose a new method for statistical inference in generalized linear models. In the overparameterized regime, Principal Component Regression (PCR) reduces variance by projecting high-dimensional data to a low-dimensional principal subspace before fitting. However, PCR incurs truncation bias whenever the true regression vector has mass outside the retained principal components (PC). To mitigate the bias, we propose Calibrated Principal Component Regression (CPCR), which first learns a low-variance prior in the PC subspace and then calibrates the model in the original feature space via a centered Tikhonov step. CPCR leverages cross-fitting and controls the truncation bias by softening PCR's hard cutoff. Theoretically, we calculate the out-of-sample risk in the random matrix regime, which shows that CPCR outperforms standard PCR when the regression signal has non-negligible components in low-variance directions. Empirically, CPCR consistently improves prediction across multiple overparameterized problems. The results highlight CPCR's stability and flexibility in modern overparameterized settings.
e96ed478dab8595a7dbda4cbcbee168f-Reviews.html
First provide a summary of the paper, and then address the following criteria: Quality, clarity, originality and significance. This paper proposes a simple latent factor model for one-shot learning with continuous outputs where very few observations are available. Specifically, it derives risk approximations in an asymptotic regime where the number of training examples is fixed and the number of features in the X space diverges. Based on principal component regression (PCR) estimator, two estimators including the bias-corrected estimator and the so-called oracle estimator are proposed and the bounds for the risks of these estimators are derived. These bounds provide insights into the significance of various parameters relevant to one-shot learning.
On Robustness of Principal Component Regression: Author Response
We begin by thanking all reviewers for their extremely encouraging and helpful responses. We agree that the fact we do PCR on both the training and testing covariates should be more explicitly placed in the context of transductive semi-supervised learning. We have strived to interpret our major theorem results (Thm 4.2 & Thm 5.1) by: (i) providing examples of natural generating Proposition 4.2, should be tight). Their empirical results support our theoretical guarantees.