Prediction performance, as measured by test R2, of standard, augmented, and two-level ridge regression, feature-weighted elastic net (ridge), and random forest by number of features (Panel A), sample size (Panel B), and signal-to-noise ratio (Panel C). In Panel A we fix n = 400 and SNR = 1. In Panel B we fix p = 2,000 and SNR = 1. In Panel C we fix p = 2,000 and n = 400. Results are averaged over 500 Monte Carlo replications. (See Section 3.1 for more information).