• Use qr.solve as default (instead of solve)

  • Drop collinear variables in pre_process_drdid.R (useful in drdid command but not other commands)

  • Add compatibility with R 3.5

  • Improve invertibility of outcome regression design matrix

  • Fixed links
  • Add new flags for non-unique unit identifier

  • Better handle of factor variables as covariates

  • Fix issue with NA in covariates
  • Allows for treating covariates as factor and alike when computing DiD

  • Improve error and warning handling due to collinearity and convergence issues.

  • First official version of package, functions for computing a variety of difference-in-differences (DiD) estimators for the ATT.

  • Documentation is improved compared to the devel version, including examples for every function now.

  • Created wrapper function drdid, ordid and ipwdid to implement doubly-robust, outcome regression and inverse probability weighted DID estimators.

  • Add dataset used in the empirical application of Sant’Anna and Zhao (2020).