Skill: /causal — OpenCausalInf Causal Inference Toolkit

Purpose

Multi-mode skill for causal inference when experiments aren't possible. Helps users estimate treatment effects from observational data with explicit assumption checking, sensitivity analysis, and mandatory caveats. Uses coded helpers from helpers/stats/experiment_stats/causal/.

When to Use

Invoke as /causal [mode] or trigger on causal inference intents:

• "Did this feature actually cause the improvement?"
• "We can't run an experiment, but..."
• "Was this change responsible for the metric movement?"
• "Can we measure the impact retroactively?"

Modes

/causal select

Purpose: Walk the method selection decision tree and recommend a causal method. Agent: agents/causal/causal-method-selector.md Flow:

1. Ask 4-6 diagnostic questions:
   • Can you randomize? → Route to /experiment design
   • Do you have a comparison group?
   • Do you have pre-treatment data?
   • Are there observable confounders you can measure?
   • How many time periods do you have?
2. Recommend: Pre-Post, DiD, PSM, Regression Adjustment, or "not feasible"
3. Output: recommended method + confidence level + rationale Checkpoint: Method confirmation (Type C — user must confirm before analysis)

/causal analyze

Purpose: Run the selected causal method on data. Agent: agents/causal/causal-analyzer.md Flow:

1. Read selected method from previous step or user input
2. Dispatch to appropriate helper:

   from helpers.stats.experiment_stats.causal import (
       pre_post_analysis, did_basic, propensity_match,
       regression_adjust,
   )
   # Method routing:
   # "pre_post" → pre_post_analysis(pre, post, covariates)
   # "did"      → did_basic(df, outcome, treat, post)
   # "psm"      → propensity_match(df, treat, covariates, outcome)
   # "regression" → regression_adjust(df, outcome, treatment, covariates)
   

3. Generate charts (treatment effect, balance plots for PSM, event study for DiD)
4. Output: working/causal_analysis_results.json

/causal check

Purpose: Run assumption checks for the selected method. Agent: agents/causal/causal-assumption-checker.md Flow:

1. Identify which assumptions apply to the selected method:
   • DiD: Parallel trends, no anticipation, stable composition
   • PSM: Common support, balance (SMD < 0.1), positivity
   • Pre-Post: No concurrent events, trend stability
   • Regression: All confounders included, correct specification
2. Run quantitative checks:

   from helpers.stats.experiment_stats.causal import (
       check_parallel_trends, check_common_support,
       balance_table,
   )
   

3. Output: per-assumption PASS / WARNING / FAIL verdicts Checkpoint: Any FAIL (Type C) → present options: adjust method, add caveats, or abort

/causal sensitivity

Purpose: Test how robust the estimate is to unmeasured confounding. Agent: agents/causal/causal-sensitivity.md Flow:

1. Run sensitivity analysis based on method:

   from helpers.stats.experiment_stats.causal import rosenbaum_bounds, e_value
   # PSM: rosenbaum_bounds(treated_outcomes, control_outcomes)
   # All: e_value(risk_ratio, ci_lower)
   

2. Translate to plain language: "An unmeasured confounder would need to be X times stronger than anything we measured to explain away this result."
3. Output: sensitivity report

/causal report

Purpose: Generate a report with mandatory caveats. Agent: agents/causal/causal-report-generator.md Flow:

1. Compile: estimate + CI + assumption verdicts + sensitivity results
2. Place on confidence ladder (RCT > DiD+reg > PSM > DiD > regression > pre-post)
3. Include mandatory caveat block (method-specific, non-negotiable)
4. Output: outputs/causal_report_{{DATE}}.md

/causal full

Purpose: End-to-end: select → analyze → check → sensitivity → report. Flow: Runs all modes in sequence. All Type C checkpoints fire.

Confidence Ladder

Methods ranked by causal credibility (highest to lowest):

Level	Method	Confidence
1	RCT (Randomized Experiment)	HIGH
2	DiD + Regression Adjustment	MODERATE-HIGH
3	PSM (Good Overlap + Balance)	MODERATE
4	DiD (Parallel Trends OK)	MODERATE
5	Regression Adjustment	LOW-MODERATE
6	Pre-Post (With Trend)	LOW
7	Pre-Post (Simple)	VERY LOW

Mandatory Caveats (Non-Negotiable)

Every causal report MUST include the method-specific caveat. These are architecturally required — the agent cannot produce a report without them.

Method	Mandatory Caveat
Pre-Post	"Assumes nothing else changed during this period. Any concurrent event could explain this result."
DiD	"Assumes the control group would have followed the same trend. Plausible but unprovable."
PSM	"Controls for observed confounders only. Unmeasured factors could bias this estimate."
Regression	"Assumes all relevant confounders are included and the model is correctly specified."

Helper Function Reference

Function	Module	Use For
pre_post_analysis()	causal.pre_post	Pre-post comparison
did_basic()	causal.did	2x2 DiD estimator
parallel_trends_test()	causal.did	Test parallel trends assumption
event_study()	causal.did	Period-by-period effects
propensity_match()	causal.matching	PSM pipeline
balance_table()	causal.balance	SMD balance diagnostics
love_plot()	causal.balance	Before/after balance visual
regression_adjust()	causal.regression	OLS with covariates
rosenbaum_bounds()	causal.sensitivity	PSM sensitivity
e_value()	causal.sensitivity	Universal sensitivity measure
check_parallel_trends()	causal.assumptions	DiD assumption
check_common_support()	causal.assumptions	PSM assumption

Cross-Product Handoffs

• /causal select → "Can you randomize? YES" → suggest /experiment design
• /experiment power → NOT_VIABLE → suggest /causal select
• /causal check → All assumptions FAIL → suggest redesign or descriptive-only analysis

State Management

analyses/{slug}/
├── causal_config.yaml       # Method selection + parameters (tracked)
├── working/                  # Intermediates (gitignored)
│   ├── causal_analysis_results.json
│   ├── assumption_report.md
│   └── sensitivity_report.md
└── outputs/                  # Final reports (per-analysis run folder)
    └── causal_report_{{DATE}}.md