Research map / Learning theory and algorithms / Kernels and regression theory
Spurious Correlations in High Dimensional Regression: The Roles of Regularization, Simplicity Bias and Over-Parameterization
Read the paperCheck your idea against 108,967 papers
AI-extracted summary. Written by AI from the paper's full text. Numbers and claims can be wrong or missing context, so check the paper before you cite or build on it.
Characterizes spurious correlations learned by ridge regression in high dimensions via a deterministic covariance-based quantity, links it to Schur complement and spurious-feature simplicity, shows a regularization trade-off with test loss, and proves random features equal regularized linear regression.
Problem
How much ERM-learned linear and random-features regression models rely on spurious features correlated with labels in high-dimensional data, and how this depends on ridge regularization, feature simplicity, and over-parameterization.
Approach
Defines a covariance-based spurious correlation measure C for regression, shows for ridge regression it concentrates around a deterministic quantity C^Σ(λ) expressed via the data covariance and an effective regularizer τ(λ), bounds it using the Schur complement and spectrum of the spurious covariance, and proves random-features models are asymptotically equivalent to ridge regression with an effec
Key results
- Proves E_E[C]=0 for unregularized linear regression and |C| = O(log d / sqrt d) w.h.p. when n = omega(d).
- Shows the optimal regularization minimizing test loss lies in an interval (0, lambda_C] where spurious correlation C is positive and increasing, under condition 2d/n bound.
- Proves random features model with p = omega(n log^4 n) is asymptotically equivalent to ridge regression with effective regularization tilde-lambda = 2 tilde-mu^2 d/(mu_1^2 n) + 2d lambda/(mu_1^2 p), so ridgeless RF has positive effective regularization.
Measured effects reported in the paper
| What was changed | Where | Measured | Effect |
|---|---|---|---|
| Set ridge regularization above zero rather than using the unregularized linear-regression solution | Linear regression · High-dimensional regression | spurious correlation | Helped |
| Use zero ridge regularization instead of positive ridge regularization | Linear regression · High-dimensional regression | spurious correlation | Helped |
| Increase the regularization strength | Linear regression · High-dimensional regression | spurious correlation | Mixed |
| Increase the strength of correlation between core and spurious features | Linear regression · Gaussian data | spurious correlation | Helped |
| Make the spurious feature easier by reducing whitening | Linear regression · CIFAR-10 (boat and truck classes) | spurious correlation | Helped |
| Increase ridge regularization from zero in the Color-MNIST and CIFAR-10 neural-network experiments | Over-parameterized two-layer neural network · Color-MNIST and CIFAR-10 | spurious correlation | Mixed |
| Use the tanh activation rather than φ₁ = h₁ + 0.1 h₃ | Over-parameterized random-features model · Random-features experiments | spurious correlation at λ = 0 | Mixed |
Surprising findings
- Unregularized linear regression learns no spurious correlation, yet ridgeless random features (e.g., tanh) do, because of an implicit effective regularization.
- Spurious correlations can reduce in-distribution test loss, even though they hurt out-of-distribution loss.
Limitations
- Results are asymptotic in the proportional regime n = Theta(d) or require n = omega(d) for the simpler bound; analysis restricted to linear regression and random features.
- Assumes Gaussian data (relaxed to Lipschitz concentration for RF) and specific odd, Lipschitz activation with nonzero first Hermite coefficient.
- Experiments on neural networks are qualitative; the theory does not directly cover deep networks trained by SGD.
Experimental setup
Datasets: Gaussian synthetic data Color-MNIST CIFAR-10
Benchmarks: Gaussian synthetic data Color-MNIST CIFAR-10
Metrics: spurious correlation C in-distribution test loss L out-of-distribution test loss lower bound
Baselines: ridgeless linear regression two-layer neural network trained on Color-MNIST and CIFAR-10
Builds on: convex Gaussian min-max theorem random features model Gaussian sequence model characterization of ridge regression
Closest papers by meaning
- Let Samples Speak: Mitigating Spurious Correlation by Exploiting the Clusterness of Samples (CVPR 2025 · similarity 0.88)
- High-Dimensional Analysis for Generalized Nonlinear Regression: From Asymptotics to Algorithm (AAAI 2024 · similarity 0.88)
- Complexity Matters: Feature Learning in the Presence of Spurious Correlations (ICML 2024 · similarity 0.87)
- Overfitting Behaviour of Gaussian Kernel Ridgeless Regression: Varying Bandwidth or Dimensionality (NeurIPS 2024 · similarity 0.86)
- Risk and cross validation in ridge regression with correlated samples (ICML 2025 · similarity 0.86)
- Dimension-free deterministic equivalents and scaling laws for random feature regression (NeurIPS 2024 · similarity 0.85)
Writing a paper in this area? scime draft is a free LaTeX editor with AI included, real-time co-authors and a check of your references and venue rules before you submit. It also imports OpenAI Prism projects.
