@article{Takumi Hattori2026,
  title={Wald-Difference-in-Differences Estimation without Individual-level Treatment Data},
  author={Takumi Hattori and Kohsuke Kubota and Keiichi Ochiai},
  journal={Journal of Information Processing},
  volume={34},
  number={ },
  pages={95-102},
  year={2026},
  doi={10.2197/ipsjjip.34.95}
}