Picture of rows of numbers. Photo by Mika Baumeister on Unsplash.

clubSandwich

Project Description

clubSandwich is a popular R package (in the top 10 percent of all R package downloads) that provides several cluster-robust variance estimators for ordinary and weighted least squares linear regression models, two-stage least squares regression models, and generalized linear models. Several adjustments are incorporated to improve small-sample performance. The package follows an object-oriented design to allow for straight-forward extension to other classes of regression models.

Interns working on clubSandwich are responsible for learning about statistical models that are not currently supported, developing required methods so that the package works for those models, and writing unit tests and examples to verify correct implementation.

Mentor

James E. Pustejovsky

Interns

Hazim Izani (Spring 2026)
Samuel Pekofsky (Spring and Summer 2025)

Lightning Talks

Samuel Pekofsky, Summer 2025