Instrumental-Variables Regression by '2SLS', '2SM', or '2SMM', with Diagnostics R package ivreg version 0.6-8 CRAN Task View: CausalInference (https://CRAN.R-project.org/view=CausalInference) CRAN Task View: Econometrics (https://CRAN.R-project.org/view=Econometrics) Instrumental variable estimation for linear models by two-stage least-squares (2SLS) regression or by robust-regression via M-estimation (2SM) or MM-estimation (2SMM). The main ivreg() model-fitting function is designed to provide a workflow as similar as possible to standard lm() regression. A wide range of methods is provided for fitted ivreg model objects, including extensive functionality for computing and graphing regression diagnostics in addition to other standard model tools. Software Depends: R (>= 3.6.0) Imports: car (>= 3.0-9), Formula, lmtest, MASS, stats Suggests: AER, effects (>= 4.2.0), knitr, insight, parallel, rmarkdown, sandwich, testthat, modelsummary, gt, ggplot2 Achim Zeileis <Achim.Zeileis@R-project.org> Comprehensive R Archive Network (CRAN) John Fox [aut] (ORCID: <https://orcid.org/0000-0002-1196-8012>), Christian Kleiber [aut] (ORCID: <https://orcid.org/0000-0002-6781-4733>), Achim Zeileis [aut, cre] (ORCID: <https://orcid.org/0000-0003-0918-3766>), Nikolas Kuschnig [ctb] (ORCID: <https://orcid.org/0000-0002-6642-2543>), R Core Team [ctb] GPL (>= 2) 2026-07-10 application/tgz https://CRAN.R-project.org/package=ivreg doi:10.32614/CRAN.package.ivreg