How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
A small first stage magnifies reduced-form changes
Example
Consider two hypothetical pairs of observed mean contrasts. In each, the first-stage contrast is ; the reduced-form contrasts are and . The ratio formula gives and , respectively. This is arithmetic illustrating the ratio's sensitivity to a small denominator; it makes no claim about a sampling distribution, estimator variance, or causal validity.
Facts & Assumptions
Given: and, in turn, or . Compute the two Wald ratios and their difference.
The Wald ratio is when . (Binary-instrument Wald ratio)
Verification
Since , the two ratios are defined by [F1] and equal and .
Their difference is , exactly the reduced-form change divided by the common first stage . The calculation is a property of the ratio only and implies no sampling or causal conclusion.
Depends on
Used by
Nothing in the library uses this result yet.
Dependency tree · two levels
2 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.
Sources
- Hernán and Robins, Causal Inference: What If, Chapter 16, §§16.2 and 16.5, printed pp. 212–222 (standard reference, not scraped)
- Hyunseung Kang, Causal Inference: Identification Under Unmeasured Confounding (Instrumental Variables), instrument strength and LATE sections (standard reference, not scraped)