{
  "citation": "Huntington-Klein, N. (2021). The Effect: An Introduction to Research Design and Causality, chapter 18 (Difference-in-Differences), Table 18.2: a textbook replication of Kessler, J. B. and Roth, A. E. (2014), Don't Take 'No' for an Answer: An Experiment with Actual Organ Donor Registrations (NBER Working Paper 20378).",
  "deviation_evidence": null,
  "doi": null,
  "excerpt": "Treatment −0.022*** (0.006)",
  "independent": null,
  "item_set": null,
  "kind": "textbook",
  "known_deviation": null,
  "licence": "The Effect is copyrighted (CRC Press, 2021; free online edition); cited, not reproduced.",
  "locator": "The Effect, Table 18.2 (difference-in-differences estimate of the effect of active-choice phrasing on organ donor rates), row 'Treatment', column 'Organ Donation Rate'",
  "metric": null,
  "n_items": null,
  "page": "online edition, chapter 18, section 18.2.1, Table 18.2",
  "read_copy_sha256": "9bddd00aee9a5748158fb8a636ca1ccccf6c18e097e7cc041798462f4c8830b8",
  "retrieved_at": "2026-10-15",
  "se": 0.006,
  "se_as_published": "0.006",
  "source_id": "kessler_roth_2014.t18_2_twfe.paper",
  "tolerance_reason": null,
  "units": "organ donor registration rate (share) per unit of the treatment indicator",
  "url": "https://theeffectbook.net/ch-DifferenceinDifference.html",
  "value": -0.022,
  "value_as_published": "−0.022",
  "verified_by": "primary_source",
  "verified_note": "Read on 2026-10-15 from the free online edition of The Effect (theeffectbook.net, chapter 18 HTML, section 18.2.1). The table comes from the book's own code, shown beside it: R feols(Rate ~ Treated | State + Quarter, vcov = ~State) on causaldata's organ_donations, Treated = California in Q32011, Q42011 or Q12012 (Stata reghdfe ... vce(cluster state); Python linearmodels PanelOLS with entity and time effects, clustered by entity). The table notes say 'Standard errors clustered at the state level'; Num.Obs. 162. This is a textbook replication of Kessler and Roth (2014), not a table of the paper. Data facts checked before any estimate: 27 states by 6 quarters, 162 rows, no missing values."
}