igerber · igerber · Aug 20, 2026 · Aug 20, 2026 · Aug 20, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,33 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- **LPDiD non-absorbing SEs now anchored against the authors' Stata `lpdid` package
+  end-to-end (no library behavior change).** New committed-golden arm
+  (`benchmarks/stata/generate_lpdid_nonabsorbing_golden.do` →
+  `benchmarks/data/lpdid_nonabsorbing_stata_golden.json`, consumed by
+  `tests/test_lpdid_nonabsorbing_stata_parity.py`) running SSC `lpdid` v1.0.3 —
+  the package builds its own clean samples, unlike the hand-reconstructed
+  `teffects` RA arm. First external anchors for the non-absorbing REWEIGHTED SE
+  (previously pinned-only via `RW_SE_PIN` with a documented ~5e-5 feols
+  weighted-cluster convention gap — the package matches the library convention to
+  ~1e-9), the non-absorbing POOLED windows (points and SEs), and the Eq. 12
+  reweighted point. Scoping: `first_entry` (Eq. 12 ==
+  `nonabsorbing(, firsttreat notyet)`) agrees on every surface of the committed
+  panel (all event-study horizons incl. placebos + both pooled windows; att
+  ~1e-14 vw / ~1.3e-8 rw, SE ~6e-17 vw / ~2.3e-9 rw); `effect_stabilization`
+  (Eq. 13 == `nonabsorbing(L)`) agrees at post horizons + pooled post on a
+  convention-neutral 47-unit subsample (att ~1.1e-14 / ~1.9e-8, SE ~1.8e-16 /
+  ~1.6e-9). Three reference-package convention differences were measured,
+  adjudicated against the paper's Eq. 13 text, and locked by
+  divergence-documentation gates: the package effectively requires L+1 untreated
+  periods before re-entry (stricter than Eq. 13's stated levels condition, which
+  the library implements), admits always-treated units as early-period controls
+  via missing-lag boundary semantics (paper-silent surface), and builds placebo
+  samples by recursive lagged intersection rather than the library's backward
+  window (paper-silent). Eq. 13 full-panel and placebo/pooled-pre inference
+  remain outside the Stata anchor and are documented as such (REGISTRY `## LPDiD`
+  Deviation 4; `DEFERRED.md` non-absorbing row narrowed to the RA +
+  placebo/pooled-pre residuals).
 - **LWDiD tutorial notebook** (`docs/tutorials/31_lwdid.ipynb`): the replacement for
   the tutorial withdrawn from PR #588, authored via the numbers-locked workflow (every
   cited number prototyped in scripts first, notebook assembled and executed once).

diff --git a/DEFERRED.md b/DEFERRED.md
@@ -65,7 +65,7 @@ exists but parity can't be verified without a local toolchain.
 | `HeterogeneousAdoptionDiD` Stute-family Stata-bridge parity: no public R `Stutetest` package exists; would add `benchmarks/stata/generate_stute_golden.do` + a Stata dependency. | `benchmarks/stata/`, `tests/test_stute_test_parity.py` | follow-up | Low |
 | **`LPDiD` regression-adjustment SE — Stata-`teffects` anchored; optional R follow-up only.** The RA influence-function cluster SE is canonically Stata `teffects ra ... atet vce(cluster)` (no R package computes it — `alexCardazzi/lpdid` does direct covariate inclusion, not RA). **Resolved:** `benchmarks/stata/generate_lpdid_ra_golden.do` reconstructs each horizon's clean sample independently and anchors the SE against `teffects` to ~1e-16 at all 7 horizons (golden `lpdid_ra_stata_golden.json`; `tests/test_lpdid_ra_stata_parity.py`, which also gates the Stata row count vs the library `n_obs`); the point is triple-anchored (Python/R/Stata). Stata is node-locked (not in CI), so the CI-runnable guards remain the regression pin (`RA_SE_PIN`) + MC coverage (`coverage_lpdid_ra.py`). *Optional residual (no longer a blocker):* contribute an RA path to `alexCardazzi/lpdid` so a runnable **R** reference also exists. | `benchmarks/stata/generate_lpdid_ra_golden.do`, `tests/test_lpdid_ra_stata_parity.py` | #B2 · Stata arm | Low |
 | **`LPDiD` survey scope gaps (PR-D1 deferrals).** Survey support covers the variance-weighted default path only. (a) `survey_design` + `reweight=True` (the equally-weighted / regression-adjustment IF path) is rejected: the weighted RA influence-function variance has **no runnable survey reference** (same class as the RA-SE row above - `survey::svyglm` anchors only the OLS/WLS path). (b) Replicate-weight survey designs (BRR/Fay/JK1/JKn/SDR) and (c) non-pweight (fweight/aweight) types are rejected pending demand. | `lpdid.py`, REGISTRY #8 | PR-D1 | Low |
-| **`LPDiD` non-absorbing SE/RA external-reference gap.** The non-absorbing *point* estimands are R-parity-locked (PR-C2: independent `fixest::feols` Eq. 12/13 reconstruction, point+SE ~1e-13/~1e-15 vw; `effect_stabilization` reweighted point + pinned SE), but the authors' canonical non-absorbing SE/RA is Stata `lpdid`/`teffects` only - no faithful R analogue exists (`alexCardazzi/lpdid`'s `nonabsorbing_lag` proved NOT a faithful Eq. 13: off-switch clamp + non-paper boundary/placebo window, diverges ~0.01-0.05 even on a monotone panel; recorded as a divergent reference, not a gate). Revisit if a Stata toolchain or a corrected R package appears - same class as the absorbing RA-SE row above. | `benchmarks/R/generate_lpdid_golden.R`, `tests/test_methodology_lpdid.py` | PR-C2 | Low |
+| **`LPDiD` non-absorbing SE/RA external-reference gap.** The authors' canonical non-absorbing SE/RA is Stata `lpdid`/`teffects` only - no faithful R analogue exists (`alexCardazzi/lpdid`'s `nonabsorbing_lag` proved NOT a faithful Eq. 13; recorded as a divergent reference, not a gate). **Resolved (SE half, scoped):** `benchmarks/stata/generate_lpdid_nonabsorbing_golden.do` runs the authors' SSC `lpdid` package end-to-end (golden `lpdid_nonabsorbing_stata_golden.json`; `tests/test_lpdid_nonabsorbing_stata_parity.py`) - Eq. 12 (`nonabsorbing(, firsttreat notyet)` == `first_entry`) anchored on ALL surfaces of the full committed panel (ES incl. placebos + both pooled windows, vw + rw; att ~1e-14/1.3e-8, SE ~6e-17/2.3e-9), Eq. 13 (`nonabsorbing(L)` == `effect_stabilization`) anchored at post horizons + pooled post on a convention-neutral 47-unit subsample (att ~1.1e-14/1.9e-8, SE ~1.8e-16/1.6e-9); first external anchors for the rw SE, the pooled windows, and the Eq. 12 rw point. Three package convention differences measured, paper-adjudicated and divergence-gated (REGISTRY `## LPDiD` Deviation 4). *Residual:* (a) non-absorbing **RA** (`rw` + covariates) - the package's RA engine is `listreg` (not `teffects`) and the committed non-absorbing panel has no covariate; needs a covariate panel + a `listreg` IF-SE convention check. (b) Eq. 13 **placebo/pooled-pre inference** - not anchored by this arm (the package's placebo-window construction differs, convention class 3; a dedicated late-entry/never-treated subsample could in principle align the two placebo constructions - a possible follow-up): the placebo ES SEs remain R-anchored (vw) / `RW_SE_PIN`-pinned (rw, h=-3/-2), and the pooled-pre SE currently has no pin or anchor of any kind (every non-absorbing R-parity fit is event-study-only and the R golden has no pooled block). | `benchmarks/stata/generate_lpdid_nonabsorbing_golden.do`, `tests/test_lpdid_nonabsorbing_stata_parity.py`, `tests/test_methodology_lpdid.py` | PR-C2 · Stata arm | Low |
 | `HeterogeneousAdoptionDiD` Phase-3 R-parity: ships coverage-rate validation on synthetic DGPs, not tight point parity vs `chaisemartin::stute_test` / `yatchew_test` (needs bootstrap-seed-semantics + `B` alignment across numpy/R). | `tests/test_had_pretests.py` | Phase 3 | Low |
 
 ## Parked — pending user demand / out of scope

diff --git a/benchmarks/R/generate_lpdid_golden.R b/benchmarks/R/generate_lpdid_golden.R
@@ -326,10 +326,12 @@ message(sprintf("Wrote golden: %s", golden_path))
 #    and ~1e-15 on SE for the variance-weighted variants (reweighted: point ~1e-13,
 #    SE has a small feols-weighted-cluster convention difference, pinned on the
 #    Python side). alexCardazzi::lpdid()'s `nonabsorbing_lag` is NOT a faithful
-#    Eq.13 (it clamps off-switches via treat_diff[<0]<-0 and uses a non-paper
-#    boundary/window convention; it diverges ~0.01-0.05 from Eq.13 even on a
-#    monotone no-off-switch panel) -> recorded in `meta` as a divergent third-party
-#    reference, NOT a parity gate (the B2 alexCardazzi-pooled precedent).
+#    Eq.13 (it clamps off-switches via treat_diff[<0]<-0, violating Eq.13's stated
+#    both-directions control condition; it also holds different boundary/placebo-
+#    window conventions on surfaces the paper does not specify; it diverges
+#    ~0.01-0.05 from Eq.13 even on a monotone no-off-switch panel) -> recorded in
+#    `meta` as a divergent third-party reference, NOT a parity gate (the B2
+#    alexCardazzi-pooled precedent).
 #
 #    APPENDED after the absorbing write_json with its OWN set.seed and distinct
 #    object names; setFixest_ssc is NOT re-called -> the absorbing panel + golden
@@ -431,8 +433,9 @@ effect_stab_rw_es <- na_es("eq13", reweight = TRUE)
 
 # ---- monotone (no-off-switch) slice: PIN the "alex diverges even without off-switches"
 # claim with committed evidence. On units whose treatment never decreases, alex's
-# off-switch clamp is inert, yet alex still diverges from the paper-faithful Eq.13 (its
-# non-paper boundary/window convention), so the recorded max post-horizon |alex - Eq.13|
+# off-switch clamp is inert, yet alex still diverges from the library's Eq.13
+# implementation (their boundary/placebo-window conventions differ on surfaces the
+# paper does not specify), so the recorded max post-horizon |alex - Eq.13|
 # is well above 0 -> documents that the divergence is NOT only off-switch handling.
 na_mono <- na_dt[, if (all(diff(treat) >= 0L)) .SD, by = unit]   # drop units with any turn-off
 na_mode <<- "eq13"

diff --git a/benchmarks/README.md b/benchmarks/README.md
@@ -54,17 +54,19 @@ and CI never needs Stata. Generators live in `stata/` and are run headless:
 STATA=/Applications/Stata/StataSE.app/Contents/MacOS/stata-se
 $STATA -b do benchmarks/stata/requirements.do            # one-time SSC install
 $STATA -b do benchmarks/stata/generate_lpdid_ra_golden.do
+$STATA -b do benchmarks/stata/generate_lpdid_nonabsorbing_golden.do
 $STATA -b do benchmarks/stata/generate_imputation_loo_golden.do
 $STATA -b do benchmarks/stata/generate_etwfe_cs_golden.do
 $STATA -b do benchmarks/stata/generate_reghdfe_kref_golden.do
 $STATA -b do benchmarks/stata/generate_lwdid_golden.do   # see stata/README.md for its warm-up step
 ```
 
-The `LPDiD` arm uses only **native** Stata commands (`teffects`), pinned by
+The `LPDiD` RA arm uses only **native** Stata commands (`teffects`), pinned by
 `version 19`. The `ImputationDiD` arm depends on SSC packages
 (`did_imputation`/`reghdfe`/`ftools`/`require`), the ETWFE/CS arm on
 `drdid`/`csdid`/`jwdid`/`hdfe`, the reghdfe K_reference arm on `reghdfe`,
-and the LWDiD arm on the authors' `lwdid`;
+the LWDiD arm on the authors' `lwdid`, and the LPDiD non-absorbing arm on the
+authors' `lpdid` (+ `boottest`/`egenmore`/`listreg`);
 `version 19` does NOT pin SSC packages
 (SSC has no version history) — install them once via `requirements.do` (the
 generators do not auto-install) and each golden records version/checksum
@@ -87,6 +89,7 @@ benchmarks/
 │   ├── README.md                          # Stata arm docs
 │   ├── requirements.do                    # one-time SSC install (did_imputation etc.)
 │   ├── generate_lpdid_ra_golden.do        # LPDiD RA SE vs teffects ra
+│   ├── generate_lpdid_nonabsorbing_golden.do  # LPDiD non-absorbing SEs vs the authors' lpdid
 │   ├── generate_imputation_loo_golden.do  # ImputationDiD LOO SE vs did_imputation leaveout
 │   ├── generate_etwfe_cs_golden.do        # ETWFE/CS vs jwdid + csdid (+ subsample ladder)
 │   ├── generate_reghdfe_kref_golden.do    # clustered CR1 K_reference vs reghdfe (disconnected panel)
@@ -113,6 +116,7 @@ benchmarks/
 | `SyntheticDiD` | `synthdid::synthdid_estimate` | Arkhangelsky et al. (2021) | ✓ Integrated |
 | `DifferenceInDifferences` | `fixest::feols` | Standard DiD | ✓ Integrated |
 | `LPDiD` (RA SE) | Stata `teffects ra ... atet` | Dube, Girardi, Jorda & Taylor (2025) | ✓ Integrated |
+| `LPDiD` (non-absorbing SEs) | Stata `lpdid, nonabsorbing(...)` (authors' package) | Dube, Girardi, Jorda & Taylor (2025) §4.2 | ✓ Integrated |
 | `ImputationDiD` (LOO SE) | Stata `did_imputation, leaveout` | Borusyak, Jaravel & Spiess (2024) App. A.9 | ✓ Integrated |
 | `WooldridgeDiD` / `CallawaySantAnna` | Stata `jwdid` / `csdid` (+ G≈20..500 SE ladder) | Wooldridge (2025) / Callaway & Sant'Anna (2021) | ✓ Integrated |
 | Clustered CR1 `K_reference` | Stata `reghdfe` + R `fixest` (disconnected-panel arms) | reghdfe/fixest ssc conventions | ✓ Integrated |

diff --git a/benchmarks/data/lpdid_nonabsorbing_stata_golden.json b/benchmarks/data/lpdid_nonabsorbing_stata_golden.json
@@ -0,0 +1,106 @@
+{
+  "meta": {
+    "estimator": "LPDiD non-absorbing SEs - authors' Stata lpdid package, end-to-end",
+    "generator": "benchmarks/stata/generate_lpdid_nonabsorbing_golden.do",
+    "source_panel": "benchmarks/data/lpdid_nonabsorbing_panel.csv",
+    "source_sha256": "71af98c96dec08abc281002b7b88df74033dac7d0ff7707eff9f3ee0c30a3964",
+    "cmd": "lpdid y, unit(unit) time(time) treat(treat) pre_window(3) post_window(4) nograph + nonabsorbing(, firsttreat notyet) [rw] on the full panel; nonabsorbing(3) [rw] on the subsample and (only_event, vw) on the full panel",
+    "mapping": "nonabsorbing(, firsttreat notyet) == first_entry; nonabsorbing(L) == effect_stabilization",
+    "drop_rule": "min(treat)==1 | any(dD==1 & L3.dD==-1)",
+    "point_anchor": "first_entry vw tau0 gated in-.do vs the committed R golden first_entry[0] att (R-anchored); effect_stab_sub vw tau0 vs the library point (library-anchored, informational); the Python test is authoritative for every surface",
+    "se_convention": "package reghdfe vce(cluster unit) CR1; the library's cluster SE matches at ~1e-16 (vw) / ~1e-9 (rw) on identical samples",
+    "convention_notes": "effect_stab full-panel and placebo/pooled-pre rows are DIVERGENCE DOCUMENTATION, not parity: the package admits always-treated units at early t via missing-lag semantics, requires L+1 untreated periods before re-entry (stricter than JAE Eq. 13's levels condition), and builds placebo samples by recursive lagged intersection; see REGISTRY ## LPDiD Deviation 4",
+    "ssc_versions": {
+      "lpdid": "lpdid program, version 1.0.3 [checksum:3687664943 len:48365]",
+      "reghdfe": "version 6.13.1 10Jan2026 [checksum:973401092 len:30978]",
+      "ftools": "version 2.50.0 09jan2026 [checksum:3739654356 len:1428]",
+      "require": "version 1.3.1 19sep2023 [checksum:1262842970 len:34415]",
+      "boottest": "boottest 4.5.3 5 June 2026 [checksum:2334657244 len:63528]",
+      "listreg": "version 1.0.3  26apr2025  Ben Jann [checksum:1074534106 len:23815]",
+      "egenmore": "1.1.1 NJC 19 March 2006 [checksum:2753673312 len:1164]",
+      "egenmore_gclsst": "1.0.0 NJC 11 January 2000 [checksum:885642367 len:916]"
+    },
+    "dropped_units": [24, 25, 27, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40],
+    "stata_edition": "SE",
+    "stata_version": 19.0,
+    "pre_window": 3,
+    "post_window": 4,
+    "stabilization_window": 3,
+    "n_rows_full": 840,
+    "n_rows_sub": 658
+  },
+  "first_entry": {
+    "vw": {
+      "es": {
+        "-3": {"att": -0.11058688194906449, "se": 0.083864694854006674, "N": 300},
+        "-2": {"att": -0.028508009716748425, "se": 0.059950164863315426, "N": 350},
+        "0": {"att": 1.8468153374570833, "se": 0.091536864444450375, "N": 400},
+        "1": {"att": 1.9174189184921464, "se": 0.082514757717069953, "N": 350},
+        "2": {"att": 1.9541562370690497, "se": 0.095995993613636657, "N": 298},
+        "3": {"att": 1.8430002097850104, "se": 0.093215506869608694, "N": 246},
+        "4": {"att": 1.8651045890489937, "se": 0.10344600862300475, "N": 211}
+      },
+      "pooled": {
+        "pre": {"att": -0.083163290352517599, "se": 0.060216134633611737, "N": 300},
+        "post": {"att": 1.8463774549223959, "se": 0.082239499731901228, "N": 211}
+      }
+    },
+    "rw": {
+      "es": {
+        "-3": {"att": -0.10982753532939604, "se": 0.085127249305807715, "N": 180},
+        "-2": {"att": -0.027473431971800764, "se": 0.059909786016452311, "N": 230},
+        "0": {"att": 1.8483385269860748, "se": 0.093169339989145811, "N": 230},
+        "1": {"att": 1.9098467525590781, "se": 0.082755294278197722, "N": 203},
+        "2": {"att": 1.9542651398293733, "se": 0.095993108882509365, "N": 173},
+        "3": {"att": 1.844237043489463, "se": 0.094299729259659446, "N": 123},
+        "4": {"att": 1.8646288450757691, "se": 0.10524070978446542, "N": 118}
+      },
+      "pooled": {
+        "pre": {"att": -0.080380126038013866, "se": 0.061217606891681819, "N": 180},
+        "post": {"att": 1.8500925875939953, "se": 0.082980268093888879, "N": 118}
+      }
+    }
+  },
+  "effect_stab_sub": {
+    "n_rows": 658,
+    "vw": {
+      "es": {
+        "-3": {"att": -0.09724719295046115, "N": 342},
+        "-2": {"att": -0.007899289624071772, "N": 408},
+        "0": {"att": 1.8115854492490506, "se": 0.079386732581726835, "N": 484},
+        "1": {"att": 1.9300421146595237, "se": 0.072501471398279477, "N": 414},
+        "2": {"att": 1.8965697184052384, "se": 0.084395761100608244, "N": 348},
+        "3": {"att": 1.879554866833909, "se": 0.076256728580062952, "N": 279},
+        "4": {"att": 1.893416496899663, "se": 0.093768556793994276, "N": 230}
+      },
+      "pooled": {
+        "pre": {"att": -0.064656623253798173, "N": 342},
+        "post": {"att": 1.8538432413410768, "se": 0.072566538322928476, "N": 230}
+      }
+    },
+    "rw": {
+      "es": {
+        "-3": {"att": -0.09552710717227407, "N": 173},
+        "-2": {"att": -0.0054487064168838913, "N": 220},
+        "0": {"att": 1.813509946055728, "se": 0.081752780459597857, "N": 329},
+        "1": {"att": 1.9275161589672816, "se": 0.073720330196303835, "N": 305},
+        "2": {"att": 1.9026466911687787, "se": 0.085905795413003486, "N": 280},
+        "3": {"att": 1.8767692749265028, "se": 0.078313461669530404, "N": 191},
+        "4": {"att": 1.8899064444115865, "se": 0.096189906878782108, "N": 151}
+      },
+      "pooled": {
+        "pre": {"att": -0.061093488880953395, "N": 173},
+        "post": {"att": 1.8560600200442186, "se": 0.074103122657375023, "N": 151}
+      }
+    }
+  },
+  "effect_stab_full_vw": {
+    "es": {
+      "0": {"att": 1.8496401510611364, "N": 628},
+      "1": {"att": 1.9364029248640582, "N": 544},
+      "2": {"att": 1.9088763162649005, "N": 463},
+      "3": {"att": 1.9438383345066086, "N": 380},
+      "4": {"att": 1.9261821895864399, "N": 320}
+    }
+  }
+}