FA-12678 / Causal analysis data contracts / Member archive

A two-period design subtracts levels instead of changes · case 03

A two-period design subtracts levels instead of changes.

Member previewVariant 3 · 3 implementations · 6 checks per implementation

Case contract

Input [treated_pre,treated_post,control_pre,control_post] defines a synthetic two-period contrast. Return (treated_post-treated_pre)-(control_post-control_pre); this arithmetic alone does not assert parallel trends.

Why this case matters

A deterministic synthetic study model isolates this data-contract defect; outputs alone establish no real-world causal identification.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
baseline imbalance	`30`	`6`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.