# On Regularization via Early Stopping for Least Squares Regression

arXiv: https://arxiv.org/abs/2406.04425 · HTML: https://mlsanity.com/paper/2406.04425/

## Key facts

- Cited by 11 papers in the map (data through 14 Oct 2026).
- Builds on 35 of its 54 references that are in the map.
- First posted on arXiv 6 Jun 2024.

## Builds on (most cited first, 30 of 35)

- [PyTorch: An Imperative Style, High-Performance Deep Learning Library](https://mlsanity.com/paper/1912.01703/) (2019)
- [SGDR: Stochastic Gradient Descent with Warm Restarts](https://mlsanity.com/paper/1608.03983/) (2016)
- [Neural Tangent Kernel: Convergence and Generalization in Neural Networks](https://mlsanity.com/paper/1806.07572/) (2018)
- [On Lazy Training in Differentiable Programming](https://mlsanity.com/paper/1812.07956/) (2018)
- [Benign Overfitting in Linear Regression](https://mlsanity.com/paper/1906.11300/) (2019)
- [Surprises in High-Dimensional Ridgeless Least Squares Interpolation](https://mlsanity.com/paper/1903.08560/) (2019)
- [High-dimensional dynamics of generalization error in neural networks](https://mlsanity.com/paper/1710.03667/) (2017)
- [SGD: General Analysis and Improved Rates](https://mlsanity.com/paper/1901.09401/) (2019)
- [High-Dimensional Asymptotics of Prediction: Ridge Regression and Classification](https://mlsanity.com/paper/1507.03003/) (2015)
- [Optimal Regularization Can Mitigate Double Descent](https://mlsanity.com/paper/2003.01897/) (2020)
- [Grokking as the Transition from Lazy to Rich Training Dynamics](https://mlsanity.com/paper/2310.06110/) (2023)
- [Early stopping and non-parametric regression: An optimal data-dependent stopping rule](https://mlsanity.com/paper/1306.3574/) (2013)
- [Benign Overfitting of Constant-Stepsize SGD for Linear Regression](https://mlsanity.com/paper/2103.12692/) (2021)
- [A Continuous-Time View of Early Stopping for Least Squares](https://mlsanity.com/paper/1810.10082/) (2018)
- [The Implicit Regularization of Stochastic Gradient Flow for Least Squares](https://mlsanity.com/paper/2003.07802/) (2020)
- [Implicit Regularization of Random Feature Models](https://mlsanity.com/paper/2002.08404/) (2020)
- [Kernel Alignment Risk Estimator: Risk Prediction from Training Data](https://mlsanity.com/paper/2006.09796/) (2020)
- [Optimal ridge penalty for real-world high-dimensional data can be zero or negative due to the implicit ridge regularization](https://mlsanity.com/paper/1805.10939/) (2018)
- [Dimension free ridge regression](https://mlsanity.com/paper/2210.08571/) (2022)
- [A Theory of Non-Linear Feature Learning with One Gradient Step in Two-Layer Neural Networks](https://mlsanity.com/paper/2310.07891/) (2023)
- [Homogenization of SGD in high-dimensions: Exact dynamics and generalization properties](https://mlsanity.com/paper/2205.07069/) (2022)
- [Nonlinear spiked covariance matrices and signal propagation in deep neural networks](https://mlsanity.com/paper/2402.10127/) (2024)
- [Grokking in Linear Estimators -- A Solvable Model that Groks without Understanding](https://mlsanity.com/paper/2310.16441/) (2023)
- [Covariate Shift in High-Dimensional Random Feature Regression](https://mlsanity.com/paper/2111.08234/) (2021)
- [Implicit Regularization or Implicit Conditioning? Exact Risk Trajectories of SGD in High Dimensions](https://mlsanity.com/paper/2206.07252/) (2022)
- [Online Robust Regression via SGD on the l1 loss](https://mlsanity.com/paper/2007.00399/) (2020)
- [High-dimensional Asymptotics of Denoising Autoencoders](https://mlsanity.com/paper/2305.11041/) (2023)
- [On the Inherent Regularization Effects of Noise Injection During Training](https://mlsanity.com/paper/2102.07379/) (2021)
- [Early alignment in two-layer networks training is a two-edged sword](https://mlsanity.com/paper/2401.10791/) (2024)
- [Double Descent and Overfitting under Noisy Inputs and Distribution Shift for Linear Denoisers](https://mlsanity.com/paper/2305.17297/) (2023)

## Built on by (most cited first, 11 of 11)

- [Theory of Scaling Laws for In-Context Regression: Depth, Width, Context and Time](https://mlsanity.com/paper/2510.01098/) (2025)
- [Models of Heavy-Tailed Mechanistic Universality](https://mlsanity.com/paper/2506.03470/) (2025)
- [Benefits of Early Stopping in Gradient Descent for Overparameterized Logistic Regression](https://mlsanity.com/paper/2502.13283/) (2025)
- [Design Considerations in Offline Preference-based RL](https://mlsanity.com/paper/2502.06861/) (2025)
- [Learning Curves of Stochastic Gradient Descent in Kernel Regression](https://mlsanity.com/paper/2505.22048/) (2025)
- [Basic Inequalities for First-Order Optimization with Applications to Statistical Risk Analysis](https://mlsanity.com/paper/2512.24999/) (2025)
- [Conservative neural posterior estimation via distributionally robust training](https://mlsanity.com/paper/2605.28516/) (2026)
- [Ridge Regression from Poisson Resetting: A Renewal Perspective on Spectral Regularization](https://mlsanity.com/paper/2605.30059/) (2026)
- [Beyond Negative-Ridge Endpoints: Mixed-Sign Spectral Regularization via Negative-Shifted Gradient Descent](https://mlsanity.com/paper/2607.22474/) (2026)
- [A Data-dependent Early Stopping Rule using Rademacher Complexity with L1-norm](https://mlsanity.com/paper/2608.24210/) (2026)
- [Why Heavy-Tailed Weight Spectra Predict Model Quality](https://mlsanity.com/paper/2610.13123/) (2026)

## Abstract (arXiv)

A fundamental problem in machine learning is understanding the effect of early stopping on the parameters obtained and the generalization capabilities of the model. Even for linear models, the effect is not fully understood for arbitrary learning rates and data. In this paper, we analyze the dynamics of discrete full batch gradient descent for linear regression. With minimal distributional assumptions, we characterize the trajectory of the parameters and the expected excess risk. Using this characterization, we show that when training with any learning rate schedule and finite time horizon, the early stopped solution is equivalent to the minimum norm solution for a generalized ridge regression problem. We also prove that early stopping is beneficial for generic data with arbitrary spectrum and for a wide variety of learning rate schedules. We provide an estimate for the optimal stopping time and empirically demonstrate the accuracy of our estimate.
