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title: "Adaptation to Environmental Change: Agriculture and the Unexpected Incidence of the Acid Rain Program"
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[Nicholas J. Sanders; Alan I. Barreca (2022)](https://doi.org/10.1257/pol.20190060). *American Economic Journal: Economic Policy*.

**Under development — community extension.** This is a provisional source-design assessment, not a new successful replication or a final eligibility ruling.

[Extension index](development.html) · [Provisional eligibility log](development.html#eligibility-log) · [Assessment JSON](aeraej-149.json) · [QMD](aeraej-149.qmd) · [Reproduction code](collection-code.zip)

## Source design and template applicability

The main agriculture targets are IV/OLS effects of continuous predicted sulfate exposure. Public binary Phase-1 emissions event studies are supplementary policy figures, not substitutes for the main crop-yield estimand; prepared agricultural analysis panels are missing.

No DiD estimates, uncertainty intervals or homogeneity-test decision were computed in this tranche. No point is added to the calibration plots. This is not a zero effect or a failed statistical test.

## Recorded treatment-column measurement

**5 distinct nonmissing values** in `SO2_Phase`.

Deposited EPA facility-year SO2 phase categories, before aggregation and event-time interactions. CSV trailing empty fields excluded. N=90,710; missing=0. Frame: source_treatment_data. Source: data/power_plants/ARP_data/EPA_facility_data.csv.

These are the existing data-measured counts, not counts inferred from design labels. A binary instrument, group indicator or interaction component need not be the treatment of interest; the source-design assessment above takes precedence for template applicability.

## Replication status

**This tranche:** unsupported design; source code/documentation inspected, no estimator run.

**Supplied library:** partial; verification: verified with blocked rows; preparation: needs_restricted_data. These are the library’s labels, not new verification claims. Missing data and unsupported designs are separate issues.

## Evidence and provenance

The following files in the supplied library were inspected. Their SHA-256 digests are recorded in the downloadable assessment JSON. Source archives and microdata are not redistributed.

- `AEJ-Policy/Sanders_Barreca_AEJ-Policy_2022_128541/R/149_sanders_barreca_replicate.R` (209 lines)
- `AEJ-Policy/Sanders_Barreca_AEJ-Policy_2022_128541/verdict.md` (118 lines)
- `AEJ-Policy/Sanders_Barreca_AEJ-Policy_2022_128541/aeraej-149.md` (229 lines)