@article{did2stwostagedifferenceindifferences,
  title = {{did2s}: Two-Stage Difference-in-Differences},
  author = {Kyle Butts and John Gardner},
  year = {2021},
  eprint = {2109.05913},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2109.05913v2},
}