Agent Conversation: anthropic/claude-opus-4.6
Task: causal-treatment-effect
Causal Treatment Effect Estimation
Research Question
Design a novel estimator for Conditional Average Treatment Effects (CATE) from observational data that is accurate, robust to confounding, and generalizes across datasets with different data generating processes.
Background
Estimating heterogeneous treatment effects -- how the causal effect of a treatment varies across individuals -- is a core problem in causal inference. Given observational data with covariates X, binary treatment T, and outcome Y, the goal is to estimate tau(x) = E[Y(1) - Y(0) | X=x], the conditional average treatment effect (CATE).
Key challenges include:
- Confounding: Treatment assignment depends on covariates, so naive comparisons are biased
- Heterogeneity: Treatment effects vary across the covariate space in complex, nonlinear ways
- Model misspecification: The true response surfaces may not match parametric assumptions
- Double robustness: Ideally, the estimator is consistent if either the outcome model or propensity model is correct
Classical approaches include S-Learner (single model), T-Learner (separate models), and IPW (propensity reweighting). Modern SOTA methods include Causal Forests (Athey & Wager, 2018), DR-Learner (Kennedy, 2023), and R-Learner (Nie & Wager, 2021), which use orthogonalization/debiasing to achieve better convergence rates.
Task
Modify the CATEEstimator class in custom_cate.py. Your estimator must implement:
fit(X, T, Y) -> self: Learn from observational datapredict(X) -> tau_hat: Predict individual treatment effects
You have access to scikit-learn and numpy/scipy. Consider novel approaches such as:
- New meta-learner architectures combining multiple debiasing strategies
- Adaptive ensemble methods that weight different estimators based on data characteristics
- Improved nuisance parameter estimation or cross-fitting procedures
- Kernel-based or local polynomial methods for CATE
- Representation learning that separates confounding from treatment effect heterogeneity
Evaluation
Evaluated on three semi-synthetic benchmarks with known ground-truth treatment effects:
- IHDP: Infant Health and Development Program (n=747, p=25, nonlinear effects)
- Jobs: Job training program evaluation (n=2000, p=10, economic outcomes)
- ACIC: Atlantic Causal Inference Conference simulation (n=4000, p=50, complex confounding)
Metrics (lower is better for both):
- PEHE: Precision in Estimation of Heterogeneous Effects = sqrt(mean((tau_hat - tau_true)^2))
- ATE error: |mean(tau_hat) - ATE_true|
Each dataset is evaluated with 5-fold cross-fitting over 10 repetitions with different random seeds.
scikit-learn/custom_cate.py [EDITABLE — lines 345–418 only]
1: # Custom CATE Estimator for MLS-Bench
2: #
3: # EDITABLE section: CATEEstimator class (the treatment effect estimator).
4: # FIXED sections: everything else (data generation, evTool Input
1{
2 "op": "replace",
3 "filename": "scikit-learn/custom_cate.py",
4 "start_line": 345,
5 "end_line": 418,
6 "content": "class CATEEstimator(BaseCATEEstimator):\n \"\"\"Overlap-Stabilized DR + R-Learner Ensemble (OSDRE).\n\n Novel: Power-law propensity stabilization of DR augmentation terms\n via ow^beta shrinkage interpolates between standard DR-learner\n (unbiased, high variance) and X-learner (plug-in, low variance).\n Combined with weighted R-learner for cross-strategy robustness.\n \"\"\"\n def __init__(self):\n self.n_folds = 5\n self.beta = 0.5 # shrinkage power: 0=DR, 0.5=sqrt, 1=X-learner\n def fit(self, X, T, Y):\n n = len(Y)\n kf = KFold(n_splits=self.n_folds, shuffle=True, random_state=42)\n mu0, mu1, e_hat = np.zeros(n), np.zeros(n), np.zeros(n)\n for tr, va in kf.split(X):\n c0, c1 = T[tr] == 0, T[tr] == 1\n kw = dict(n_estimators=200, max_depth=4, learning_rate=0.1,\n min_samples_leaf=20, subsample=0.8, random_state=42)\n m0 = GradientBoostingRegressor(**kw)\n m1 = GradientBoostingRegressor(**kw)\n m0.fit(X[tr[c0]], Y[tr[c0]])\n m1.fit(X[tr[c1]], Y[tr[c1]])\n mu0[va] = m0.predict(X[va])\n mu1[va] = m1.predict(X[va])\n mt = GradientBoostingClassifier(n_estimators=200, max_depth=3,\n learning_rate=0.1, min_samples_leaf=20, subsample=0.8,\n random_state=42)\n mt.fit(X[tr], T[tr])\n e_hat[va] = mt.predict_proba(X[va])[:, 1]\n e_hat = np.clip(e_hat, 0.05, 0.95)\n tau_plug = mu1 - mu0\n # Stabilized DR: shrink augmentation by own-group propensity^beta\n # beta=0 gives standard DR, beta=1 gives X-learner, beta=0.5 is sqrt\n aug = T * (Y - mu1) / e_hat - (1 - T) * (Y - mu0) / (1 - e_hat)\n ow = T * e_hat + (1 - T) * (1 - e_hat) # own-group propensity\n dr_pseudo = tau_plug + (ow ** self.beta) * aug\n q = np.percentile(np.abs(dr_pseudo), 95)\n dr_pseudo = np.clip(dr_pseudo, -q, q)\n # R-learner: use marginal outcome from nuisance models\n m_hat = e_hat * mu1 + (1 - e_hat) * mu0\n T_res = T - e_hat\n safe = np.where(np.abs(T_res) > 0.01, T_res,\n np.sign(T_res) * 0.01 + 1e-8)\n r_pseudo = (Y - m_hat) / safe\n r_w = T_res ** 2\n qr = np.percentile(np.abs(r_pseudo), 95)\n r_pseudo = np.clip(r_pseudo, -qr, qr)\n # Final CATE models\n ckw = dict(n_estimators=300, max_depth=3, learning_rate=0.05,\n min_samples_leaf=15, subsample=0.8, random_state=42)\n self._m_dr = GradientBoostingRegressor(**ckw)\n self._m_dr.fit(X, dr_pseudo)\n self._m_rl = GradientBoostingRegressor(**ckw)\n self._m_rl.fit(X, r_pseudo, sample_weight=r_w)\n return self\n def predict(self, X):\n return 0.5 * self._m_dr.predict(X) + 0.5 * self._m_rl.predict(X)\n\n\n"
7}OK: Replaced lines 345..418 with 60 line(s) in scikit-learn/custom_cate.py. Editable range: 345–404. [Current file: scikit-learn/custom_cate.py | editable: 345–404 | total: 466 lines] 342| # EDITABLE: Custom CATE Estimator (lines 345-418) 343| # ===================================================================== 344| 345 class CATEEstimator(BaseCATEEstimator): 346 """Overlap-Stabilized DR + R-Learner Ensemble (OSDRE). 347 348 Novel: Power-law propensity stabilization of DR augmentation terms 349 via ow^beta shrinkage interpolates between standard DR-learner 350 (unbiased, high variance) and X-learner (plug-in, low variance). 351 Combined with weighted R-learner for cross-strategy robustness. 352 """ 353 def __init__(self): 354 self.n_folds = 5 355 self.beta = 0.5 # shrinkage power: 0=DR, 0.5=sqrt, 1=X-learner 356 def fit(self, X, T, Y): 357 n = len(Y) 358
Tool Input
1{
2 "op": "replace",
3 "filename": "scikit-learn/custom_cate.py",
4 "start_line": 345,
5 "end_line": 418,
6 "content": "class CATEEstimator(BaseCATEEstimator):\n \"\"\"Ensemble-Nuisance Orthogonal CATE (ENOC) estimator.\n\n Novel contributions:\n (1) Ensemble nuisance estimation: averages S-learner and T-learner\n predictions for mu0(X), mu1(X). S-learner pools all data for\n data-efficient estimation; T-learner captures group-specific\n patterns. Their average is more robust than either alone.\n (2) Multi-strategy CATE ensemble: combines DR-Learner (doubly robust),\n R-Learner (orthogonal debiasing), and S-Learner (regularized\n stability) via uniform averaging for cross-DGP robustness.\n \"\"\"\n def __init__(self):\n pass\n\n def fit(self, X, T, Y):\n n = len(Y)\n kf = KFold(n_splits=5, shuffle=True, random_state=42)\n mu0h, mu1h, mh, eh = [np.zeros(n) for _ in range(4)]\n gk = dict(n_estimators=200, max_depth=4, learning_rate=0.1,\n min_samples_leaf=20, subsample=0.8, random_state=42)\n gc = dict(n_estimators=200, max_depth=3, learning_rate=0.1,\n min_samples_leaf=20, subsample=0.8, random_state=42)\n for tr, va in kf.split(X):\n nv = len(va)\n c0, c1 = T[tr] == 0, T[tr] == 1\n # T-learner nuisance (separate models per treatment group)\n mu0t = GradientBoostingRegressor(**gk).fit(\n X[tr[c0]], Y[tr[c0]]).predict(X[va])\n mu1t = GradientBoostingRegressor(**gk).fit(\n X[tr[c1]], Y[tr[c1]]).predict(X[va])\n # S-learner nuisance (pooled model with T as feature)\n ms = GradientBoostingRegressor(**gk).fit(\n np.c_[X[tr], T[tr]], Y[tr])\n mu0s = ms.predict(np.c_[X[va], np.zeros(nv)])\n mu1s = ms.predict(np.c_[X[va], np.ones(nv)])\n # Ensemble nuisance: average for robustness\n mu0h[va] = 0.5 * mu0t + 0.5 * mu0s\n mu1h[va] = 0.5 * mu1t + 0.5 * mu1s\n # Marginal outcome E[Y|X] for R-learner\n mh[va] = GradientBoostingRegressor(**gk).fit(\n X[tr], Y[tr]).predict(X[va])\n # Propensity score\n eh[va] = GradientBoostingClassifier(**gc).fit(\n X[tr], T[tr]).predict_proba(X[va])[:, 1]\n eh = np.clip(eh, 0.05, 0.95)\n # DR pseudo-outcomes with winsorization\n dr = (mu1h - mu0h + T * (Y - mu1h) / eh\n - (1 - T) * (Y - mu0h) / (1 - eh))\n q = np.percentile(np.abs(dr), 97)\n dr = np.clip(dr, -q, q)\n # R-learner pseudo-outcomes with safe division\n Yr, Tr = Y - mh, T - eh\n sT = np.where(np.abs(Tr) > 0.01, Tr,\n np.sign(Tr + 1e-10) * 0.01)\n rp, rw = Yr / sT, Tr ** 2\n q2 = np.percentile(np.abs(rp), 95)\n rp = np.clip(rp, -q2, q2)\n # Final CATE models\n fk = dict(n_estimators=300, max_depth=3, learning_rate=0.05,\n min_samples_leaf=20, subsample=0.8, random_state=42)\n self._dr = GradientBoostingRegressor(**fk).fit(X, dr)\n self._r = GradientBoostingRegressor(**fk).fit(\n X, rp, sample_weight=rw)\n self._s = GradientBoostingRegressor(**gk).fit(\n np.c_[X, T], Y)\n return self\n\n def predict(self, X):\n n = X.shape[0]\n dp = self._dr.predict(X)\n rp = self._r.predict(X)\n sp = (self._s.predict(np.c_[X, np.ones(n)])\n - self._s.predict(np.c_[X, np.zeros(n)]))\n return (dp + rp + sp) / 3.0\n\n"
7}OK: Replaced lines 345..418 with 76 line(s) in scikit-learn/custom_cate.py. Editable range: 345–420. [Current file: scikit-learn/custom_cate.py | editable: 345–420 | total: 482 lines] 342| # EDITABLE: Custom CATE Estimator (lines 345-418) 343| # ===================================================================== 344| 345 class CATEEstimator(BaseCATEEstimator): 346 """Ensemble-Nuisance Orthogonal CATE (ENOC) estimator. 347 348 Novel contributions: 349 (1) Ensemble nuisance estimation: averages S-learner and T-learner 350 predictions for mu0(X), mu1(X). S-learner pools all data for 351 data-efficient estimation; T-learner captures group-specific 352 patterns. Their average is more robust than either alone. 353 (2) Multi-strategy CATE ensemble: combines DR-Learner (doubly robust), 354 R-Learner (orthogonal debiasing), and S-Learner (regularized 355 stability) via uniform avera
[Test #1] (2 tests remaining; call submit(n=1) to submit this result) ## Seed 42 ### ihdp (scripts/ihdp.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/ihdp.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/scikit-learn/scikit-learn/custom_cate.py': [Errno 2] No such file or directory ERROR conda.cli.main_run:execute(142): `conda run bash /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/ihdp.sh` failed. (See above for error) ### jobs (scripts/jobs.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/jobs.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/s
[Test #2] (1 test remaining; call submit(n=2) to submit this result) ### ihdp (scripts/ihdp.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/ihdp.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/scikit-learn/scikit-learn/custom_cate.py': [Errno 2] No such file or directory ERROR conda.cli.main_run:execute(142): `conda run bash /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/ihdp.sh` failed. (See above for error) ### jobs (scripts/jobs.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/jobs.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanl
[Test #3] (0 tests remaining) ## Seed 42 ### ihdp (scripts/ihdp.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/ihdp.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/scikit-learn/scikit-learn/custom_cate.py': [Errno 2] No such file or directory ERROR conda.cli.main_run:execute(142): `conda run bash /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/ihdp.sh` failed. (See above for error) ### jobs (scripts/jobs.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260402_183953/.local_scripts/scripts/jobs.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanlyu/MLS-Bench/vendor/worksp
Tool Input
1{
2 "op": "replace",
3 "filename": "scikit-learn/custom_cate.py",
4 "start_line": 345,
5 "end_line": 418,
6 "content": "class CATEEstimator(BaseCATEEstimator):\n \"\"\"Overlap-Adaptive Doubly Robust Ensemble (OADRE) for CATE.\n Novel: (1) Overlap-adaptive blending of DR correction and T-learner\n plug-in via h(x)=min(e,1-e). (2) OADR + R-learner ensemble.\n (3) Iterative influence trimming for pseudo-outcome denoising.\"\"\"\n\n def __init__(self):\n self._nf = 3\n\n def fit(self, X, T, Y):\n n = len(Y)\n kf = KFold(n_splits=self._nf, shuffle=True, random_state=42)\n mu0, mu1, mY, eX = [np.zeros(n) for _ in range(4)]\n kw = dict(n_estimators=200, max_depth=4, learning_rate=0.1,\n min_samples_leaf=15, subsample=0.8, random_state=42)\n for tr, va in kf.split(X):\n t0, t1 = T[tr] == 0, T[tr] == 1\n g0 = GradientBoostingRegressor(**kw)\n g1 = GradientBoostingRegressor(**kw)\n gm = GradientBoostingRegressor(**kw)\n g0.fit(X[tr[t0]], Y[tr[t0]]); g1.fit(X[tr[t1]], Y[tr[t1]])\n gm.fit(X[tr], Y[tr])\n mu0[va] = g0.predict(X[va])\n mu1[va] = g1.predict(X[va])\n mY[va] = gm.predict(X[va])\n gc = GradientBoostingClassifier(n_estimators=200, max_depth=3,\n learning_rate=0.1, min_samples_leaf=15, subsample=0.8, random_state=42)\n gc.fit(X[tr], T[tr])\n eX[va] = gc.predict_proba(X[va])[:, 1]\n eX = np.clip(eX, 0.05, 0.95)\n # --- OADR: overlap-adaptive DR pseudo-outcomes ---\n plugin = mu1 - mu0\n corr = T * (Y - mu1) / eX - (1 - T) * (Y - mu0) / (1 - eX)\n h = np.minimum(eX, 1 - eX)\n alpha = np.minimum(1.0, h / 0.15)\n psi_dr = plugin + alpha * corr\n vp = T / eX**2 + (1 - T) / (1 - eX)**2\n w_dr = 1.0 / (vp + np.median(vp))\n w_dr = w_dr / w_dr.mean()\n # --- R-learner pseudo-outcomes ---\n Tr, Yr = T - eX, Y - mY\n sT = np.where(np.abs(Tr) > 0.01, Tr, np.sign(Tr) * 0.01 + 1e-8)\n psi_r = Yr / sT\n q = np.percentile(np.abs(psi_r), 95)\n psi_r = np.clip(psi_r, -q, q)\n w_r = Tr ** 2\n w_r = w_r / (w_r.mean() + 1e-12)\n # --- Fit OADR with iterative influence trimming ---\n fkw = dict(n_estimators=300, max_depth=4, learning_rate=0.05,\n min_samples_leaf=15, subsample=0.8, random_state=42)\n f1 = GradientBoostingRegressor(**fkw)\n f1.fit(X, psi_dr, sample_weight=w_dr)\n dev = np.abs(psi_dr - f1.predict(X))\n thr = np.percentile(dev, 90)\n rw = w_dr * np.minimum(1.0, thr / (dev + 1e-8))\n self._f1 = GradientBoostingRegressor(**fkw)\n self._f1.fit(X, psi_dr, sample_weight=rw)\n # --- Fit R-learner model ---\n self._f2 = GradientBoostingRegressor(**fkw)\n self._f2.fit(X, psi_r, sample_weight=w_r)\n return self\n\n def predict(self, X):\n return 0.5 * self._f1.predict(X) + 0.5 * self._f2.predict(X)\n\n\n"
7}OK: Replaced lines 345..418 with 66 line(s) in scikit-learn/custom_cate.py. Editable range: 345–410. [Current file: scikit-learn/custom_cate.py | editable: 345–410 | total: 472 lines] 342| # EDITABLE: Custom CATE Estimator (lines 345-418) 343| # ===================================================================== 344| 345 class CATEEstimator(BaseCATEEstimator): 346 """Overlap-Adaptive Doubly Robust Ensemble (OADRE) for CATE. 347 Novel: (1) Overlap-adaptive blending of DR correction and T-learner 348 plug-in via h(x)=min(e,1-e). (2) OADR + R-learner ensemble. 349 (3) Iterative influence trimming for pseudo-outcome denoising.""" 350 351 def __init__(self): 352 self._nf = 3 353 354 def fit(self, X, T, Y): 355 n = len(Y) 356 kf = KFold(n_splits=self._nf, shuffle=True, random_state=42) 357 mu0, mu1, mY, eX = [np.zeros(n) for _ in range(4)] 358 kw = dict(n_est
[Test #1] (2 tests remaining; call submit(n=1) to submit this result) ## Seed 42 ### ihdp (scripts/ihdp.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/ihdp.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/scikit-learn/scikit-learn/custom_cate.py': [Errno 2] No such file or directory ERROR conda.cli.main_run:execute(142): `conda run bash /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/ihdp.sh` failed. (See above for error) ### jobs (scripts/jobs.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/jobs.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/s
[Test #2] (1 test remaining; call submit(n=2) to submit this result) ### ihdp (scripts/ihdp.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/ihdp.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/scikit-learn/scikit-learn/custom_cate.py': [Errno 2] No such file or directory ERROR conda.cli.main_run:execute(142): `conda run bash /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/ihdp.sh` failed. (See above for error) ### jobs (scripts/jobs.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/jobs.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanl
Tool Input
1{
2 "n": 2
3}[submit] Submitting result from test #2 as final. ### ihdp (scripts/ihdp.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/ihdp.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/scikit-learn/scikit-learn/custom_cate.py': [Errno 2] No such file or directory ERROR conda.cli.main_run:execute(142): `conda run bash /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/ihdp.sh` failed. (See above for error) ### jobs (scripts/jobs.sh) /srv/home/bohanlyu/MLS-Bench/vendor/workspace/causal-treatment-effect/anthropic_claude-opus-4.6_20260403_040422/.local_scripts/scripts/jobs.sh: line 3: cd: /workspace: No such file or directory python: can't open file '/srv/home/bohanlyu/MLS-Bench/vendor