Address PR #372 R1 review (2 P1, 2 P2, 1 P3)

P1 - docs/references.rst incomplete (5 missing citations)
- Add Baker, Larcker, Wang & Wang (2025) - "Difference-in-Differences Designs:
  A Practitioner's Guide" arXiv:2503.13323; backs the 8-step Practitioner
  Workflow now surfaced in README and llms-practitioner.txt.
- Add Callaway, Goodman-Bacon & Sant'Anna (2024) - "Difference-in-Differences
  with a Continuous Treatment" NBER WP 32117; backs ContinuousDiD (under new
  "Continuous Treatment DiD" section).
- Add Chen, Sant'Anna & Xie (2025) - "Efficient Difference-in-Differences and
  Event Study Estimators"; backs EfficientDiD.
- Add de Chaisemartin & D'Haultfoeuille (2022, revised 2024) NBER WP 29873;
  dynamic companion to dCDH 2020, backs the cohort-recentered plug-in
  variance formula.
- Add Wooldridge (2025) Empirical Economics + Wooldridge (2023) Econometrics
  Journal under new "Wooldridge ETWFE" sub-section; backs WooldridgeDiD's
  saturated OLS and logit/Poisson QMLE paths.

P1 - .claude/commands/docs-check.md
- Replace broken `awk '/^## Estimators/,/^## /'` (self-terminates on opening
  H2) with a flag-based extractor that skips the heading and stops at the
  next H2.
- Special-case diagnostic-class items (HonestDiD): the workflow text now
  routes them to `## Diagnostics & Sensitivity` in both llms.txt and README,
  matching the existing table.

P2 - docs/doc-deps.yaml
- Retarget HonestDiD's README entry from "Estimators (one-line catalog
  entry)" to "Diagnostics & Sensitivity (one-line entry)" so /docs-impact
  flags the correct README section.
- Add `- path: docs/references.rst` (type: user_guide) to all 18 method-
  backed source modules so /docs-impact and /pre-merge-check warnings
  surface bibliography updates when source code changes.

P2 - README.md absolute links
- L83 docs/methodology/REPORTING.md, L182 CITATION.cff, L184 CONTRIBUTORS.md
  switched to absolute https://github.com/igerber/diff-diff/blob/main/...
  URLs so they resolve on PyPI (which does not auto-resolve relative paths).

P3 - README.md tutorial count
- Drop the "18" hard-coded count in the Tutorials bullet to prevent future
  drift; repo currently has 19 notebooks.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: igerber

.claude/commands/docs-check.md

@@ -115,18 +115,38 @@ Determine which checks to run based on `$ARGUMENTS`.
 
 ### 2. llms.txt + README Catalog Check
 
-For each estimator in the table above:
-1. Read `diff_diff/guides/llms.txt` and verify the estimator name appears under `## Estimators`
-2. Read `README.md` and verify the estimator name appears in the `## Estimators` flat catalog (one-line entry)
+For each estimator/diagnostic in the table above:
+
+1. Read `diff_diff/guides/llms.txt` and verify the name appears under the right section:
+   - **Estimators** (e.g. CallawaySantAnna, SunAbraham, TROP, BaconDecomposition): under `## Estimators`
+   - **Diagnostics-class** (HonestDiD, and any future diagnostic-only entries): under `## Diagnostics and Sensitivity Analysis`
+2. Read `README.md` and verify the name appears in the matching flat catalog:
+   - **Estimators**: in the `## Estimators` section
+   - **Diagnostics-class** (HonestDiD): in the `## Diagnostics & Sensitivity` section
 3. Report missing entries
 
 ```bash
-# Example: Check that "CallawaySantAnna" appears in both llms.txt and the README catalog
+# Extract the README ## Estimators section. Use a flag-based awk because the
+# range form `awk '/^## Estimators/,/^## /'` self-terminates on the opening H2.
+extract_section() {
+  awk -v target="$1" '
+    $0 == "## " target { flag=1; next }
+    flag && /^## / { flag=0 }
+    flag { print }
+  ' README.md
+}
+
+# Example: an estimator (lives in ## Estimators)
+extract_section "Estimators" | grep -c 'CallawaySantAnna'
+
+# Example: a diagnostic (lives in ## Diagnostics & Sensitivity)
+extract_section "Diagnostics & Sensitivity" | grep -c 'Honest DiD'
+
+# Always verify both surfaces
 grep -c 'CallawaySantAnna' diff_diff/guides/llms.txt
-awk '/^## Estimators/,/^## /' README.md | grep -c 'CallawaySantAnna'
 ```
 
-Do NOT search for per-estimator README sections - they were intentionally removed in the 2026-04 docs refresh. The README's `## Estimators` heading is the only valid catalog surface.
+Do NOT search for per-estimator README sections - they were intentionally removed in the 2026-04 docs refresh. The README's `## Estimators` and `## Diagnostics & Sensitivity` headings are the only valid catalog surfaces.
 
 ### 3. Scholarly References Check
 

README.md

@@ -51,7 +51,7 @@ results.print_summary()     # full statsmodels-style table
 
 - [Quickstart](https://diff-diff.readthedocs.io/en/stable/quickstart.html) - basic 2x2 DiD with column-name and formula interfaces, covariates, fixed effects, cluster-robust SEs
 - [Choosing an Estimator](https://diff-diff.readthedocs.io/en/stable/choosing_estimator.html) - decision flowchart for picking the right estimator
-- [Tutorials](https://diff-diff.readthedocs.io/en/stable/tutorials/01_basic_did.html) - 18 hands-on Jupyter notebooks covering every estimator and design pattern
+- [Tutorials](https://diff-diff.readthedocs.io/en/stable/tutorials/01_basic_did.html) - hands-on Jupyter notebooks covering every estimator and design pattern
 - [Troubleshooting](https://diff-diff.readthedocs.io/en/stable/troubleshooting.html) - common issues and solutions
 - [R Comparison](https://diff-diff.readthedocs.io/en/stable/r_comparison.html) | [Python Comparison](https://diff-diff.readthedocs.io/en/stable/python_comparison.html) | [Benchmarks](https://diff-diff.readthedocs.io/en/stable/benchmarks.html) - validation results vs `did`, `synthdid`, `fixest`
 - [API Reference](https://diff-diff.readthedocs.io/en/stable/api/index.html) - full API for all estimators, results classes, diagnostics, utilities
@@ -80,7 +80,7 @@ Measuring campaign lift? Evaluating a product launch? Rolling out a policy in wa
 - [Brand awareness survey tutorial](https://diff-diff.readthedocs.io/en/stable/tutorials/17_brand_awareness_survey.html) - full example with complex survey design, brand funnel analysis, and staggered rollouts
 - Have BRFSS/ACS/CPS individual records? Use [`aggregate_survey()`](https://diff-diff.readthedocs.io/en/stable/api/prep.html) to roll respondent-level microdata into a geographic-period panel with inverse-variance precision weights for second-stage DiD
 
-`BusinessReport` and `DiagnosticReport` are experimental preview classes that produce plain-English output and a structured `to_dict()` schema from any fitted result - wording and schema will evolve. See [docs/methodology/REPORTING.md](docs/methodology/REPORTING.md) for usage and stability notes.
+`BusinessReport` and `DiagnosticReport` are experimental preview classes that produce plain-English output and a structured `to_dict()` schema from any fitted result - wording and schema will evolve. See [docs/methodology/REPORTING.md](https://github.com/igerber/diff-diff/blob/main/docs/methodology/REPORTING.md) for usage and stability notes.
 
 ## Practitioner Workflow (Baker et al. 2025)
 
@@ -179,9 +179,9 @@ If you use diff-diff in your research, please cite it:
 
 The DOI above is the Zenodo concept DOI - it always resolves to the latest release. To cite a specific version, look up its versioned DOI on [the Zenodo project page](https://doi.org/10.5281/zenodo.19646175).
 
-See [`CITATION.cff`](CITATION.cff) for the full citation metadata.
+See [`CITATION.cff`](https://github.com/igerber/diff-diff/blob/main/CITATION.cff) for the full citation metadata.
 
-**Note on authorship**: academic citation (`CITATION.cff`, the BibTeX above) lists individual authors with ORCIDs per scholarly convention. Package metadata surfaces (`pyproject.toml`, Sphinx docs) list "diff-diff contributors" to acknowledge the collective - see [`CONTRIBUTORS.md`](CONTRIBUTORS.md) for the full list.
+**Note on authorship**: academic citation (`CITATION.cff`, the BibTeX above) lists individual authors with ORCIDs per scholarly convention. Package metadata surfaces (`pyproject.toml`, Sphinx docs) list "diff-diff contributors" to acknowledge the collective - see [`CONTRIBUTORS.md`](https://github.com/igerber/diff-diff/blob/main/CONTRIBUTORS.md) for the full list.
 
 ## License
 

docs/doc-deps.yaml

@@ -96,6 +96,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "DifferenceInDifferences"
         type: user_guide
@@ -137,6 +139,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "CallawaySantAnna"
         type: user_guide
@@ -183,6 +187,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "SunAbraham"
         type: user_guide
@@ -206,6 +212,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "ImputationDiD"
         type: user_guide
@@ -227,6 +235,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "TwoStageDiD"
         type: user_guide
@@ -248,6 +258,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "EfficientDiD"
         type: user_guide
@@ -270,6 +282,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "ChaisemartinDHaultfoeuille"
         type: user_guide
@@ -302,6 +316,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "ContinuousDiD"
         type: user_guide
@@ -326,6 +342,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "SyntheticDiD"
         type: user_guide
@@ -352,6 +370,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "TripleDifference"
         type: user_guide
@@ -373,6 +393,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "StackedDiD"
         type: user_guide
@@ -394,6 +416,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "WooldridgeDiD"
         type: user_guide
@@ -415,6 +439,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "TROP"
         type: user_guide
@@ -436,7 +462,9 @@ sources:
       - path: docs/tutorials/05_honest_did.ipynb
         type: tutorial
       - path: README.md
-        section: "Estimators (one-line catalog entry)"
+        section: "Diagnostics & Sensitivity (one-line entry)"
+        type: user_guide
+      - path: docs/references.rst
         type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "HonestDiD"
@@ -455,6 +483,8 @@ sources:
       - path: README.md
         section: "Estimators (one-line catalog entry)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
 
   # ── Diagnostics & analysis ───────���─────────────────────────────────
 
@@ -493,6 +523,8 @@ sources:
       - path: README.md
         section: "For Data Scientists (one-line mention)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "BusinessReport"
         type: user_guide
@@ -508,6 +540,8 @@ sources:
       - path: README.md
         section: "For Data Scientists (one-line mention)"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "DiagnosticReport"
         type: user_guide
@@ -543,6 +577,8 @@ sources:
       - path: README.md
         section: "Survey Support"
         type: user_guide
+      - path: docs/references.rst
+        type: user_guide
       - path: diff_diff/guides/llms-full.txt
         section: "Survey"
         type: user_guide

docs/references.rst

@@ -19,6 +19,17 @@ Two-Way Fixed Effects
 
 - **Imai, K., & Kim, I. S. (2021).** "On the Use of Two-Way Fixed Effects Regression Models for Causal Inference with Panel Data." *Political Analysis*, 29(3), 405-415. https://doi.org/10.1017/pan.2020.33
 
+Wooldridge ETWFE
+----------------
+
+- **Wooldridge, J. M. (2025).** "Two-Way Fixed Effects, the Two-Way Mundlak Regression, and Difference-in-Differences Estimators." *Empirical Economics*, 69(5), 2545-2587. (Published version of NBER Working Paper 29154.)
+
+  Primary source for the saturated OLS ETWFE design implemented in our ``WooldridgeDiD`` class.
+
+- **Wooldridge, J. M. (2023).** "Simple Approaches to Nonlinear Difference-in-Differences with Panel Data." *The Econometrics Journal*, 26(3), C31-C66. https://doi.org/10.1093/ectj/utad016
+
+  Secondary source for the logit/Poisson QMLE (ASF-based ATT) extensions in ``WooldridgeDiD``.
+
 Robust Standard Errors
 ----------------------
 
@@ -131,10 +142,29 @@ Multi-Period and Staggered Adoption
 
 - **de Chaisemartin, C., & D'Haultfœuille, X. (2020).** "Two-Way Fixed Effects Estimators with Heterogeneous Treatment Effects." *American Economic Review*, 110(9), 2964-2996. https://doi.org/10.1257/aer.20181169
 
+- **de Chaisemartin, C., & D'Haultfœuille, X. (2022, revised 2024).** "Difference-in-Differences Estimators of Intertemporal Treatment Effects." *NBER Working Paper* 29873. https://www.nber.org/papers/w29873
+
+  Dynamic companion to the 2020 paper. Web Appendix Section 3.7.3 contains the cohort-recentered plug-in variance formula implemented in our ``ChaisemartinDHaultfoeuille`` class.
+
 - **Goodman-Bacon, A. (2021).** "Difference-in-Differences with Variation in Treatment Timing." *Journal of Econometrics*, 225(2), 254-277. https://doi.org/10.1016/j.jeconom.2021.03.014
 
 - **Wing, C., Freedman, S. M., & Hollingsworth, A. (2024).** "Stacked Difference-in-Differences." *NBER Working Paper* 32054. https://www.nber.org/papers/w32054
 
+- **Chen, X., Sant'Anna, P. H. C., & Xie, H. (2025).** "Efficient Difference-in-Differences and Event Study Estimators." *Working Paper*.
+
+  Primary source for the optimal-weighting / PT-All / PT-Post efficient DiD implemented in our ``EfficientDiD`` class.
+
+- **Baker, A. C., Larcker, D. F., Wang, C. C. Y., & Wang, X. (2025).** "Difference-in-Differences Designs: A Practitioner's Guide." *arXiv preprint* arXiv:2503.13323. https://arxiv.org/abs/2503.13323
+
+  Source for the 8-step practitioner workflow surfaced via ``diff_diff.get_llm_guide("practitioner")`` and the README ``## Practitioner Workflow`` section. See ``docs/methodology/REGISTRY.md`` for the diff-diff renumbering and per-step deviations.
+
+Continuous Treatment DiD
+------------------------
+
+- **Callaway, B., Goodman-Bacon, A., & Sant'Anna, P. H. C. (2024).** "Difference-in-Differences with a Continuous Treatment." *NBER Working Paper* 32117. https://www.nber.org/papers/w32117
+
+  Primary source for ATT(d), ACRT, dose-response curves, and B-spline flexibility implemented in our ``ContinuousDiD`` class.
+
 Power Analysis
 --------------