Equivalence Testing for Pre-Trends in Difference-in-Differences Designs R package EquiTrends version 1.0.0 Testing for parallel trends is crucial in the Difference-in-Differences framework. To this end, this package performs equivalence testing in the context of Difference-in-Differences estimation. It allows users to test if pre-treatment trends in the treated group are “equivalent” to those in the control group. Here, “equivalence” means that rejection of the null hypothesis implies that a function of the pre-treatment placebo effects (maximum absolute, average or root mean squared value) does not exceed a pre-specified threshold below which trend differences are considered negligible. The package is based on the theory developed in Dette & Schumann (2024) <doi:10.1080/07350015.2024.2308121>. Software Depends: R (>= 3.5.0) Imports: clubSandwich, nloptr, dplyr, rlang, plm, Rcpp (>= 1.0.12), RcppParallel, stats, VGAM LinkingTo: Rcpp, RcppArmadillo, RcppParallel Suggests: testthat (>= 3.0.0) Ties Bos <tc.bos@student.maastrichtuniversity.nl> Comprehensive R Archive Network (CRAN) Ties Bos [aut, cre], Martin Schumann [ctb] MIT + file LICENSE (https://CRAN.R-project.org/package=EquiTrends/LICENSE) 2024-09-03 application/tgz https://CRAN.R-project.org/package=EquiTrends doi:10.32614/CRAN.package.EquiTrends