---
title: "Labor Supply and Directed Technical Change: Evidence from the Termination of the Bracero Program in 1964"
format:
  html:
    theme: cosmo
    toc: true
    embed-resources: true
    include-in-header:
      text: |
        <style>main{overflow-wrap:anywhere;max-width:1100px!important}table{display:block;overflow:auto;font-size:.85rem}td,th{padding:6px}img{max-width:100%}p code,li code{overflow-wrap:anywhere;white-space:normal}</style>
---

[Shmuel San (2022)](https://doi.org/10.1257/app.20200664). *American Economic Journal: Applied Economics*.

**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-47.json) · [QMD](aeraej-47.qmd) · [Reproduction code](collection-code.zip)

## Source design and template applicability

The patent PPML DiD uses foreign_per_64 interacted with post as a continuous exposure. The deposited state exposure aggregate is not the required crop-year patent panel; no exposure threshold is imposed.

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

**23 distinct nonmissing values** in `exposure`.

State-level Bracero exposure input; patent outcomes are not needed to count this treatment. N=51; missing=5. Frame: selected_source_data. Source: /Volumes/LAL_BAK/did-cardinality-work/packages/San_AEJ-Applied_2022_148101/data/input/dta/exposure_state.dta.

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:** rebuild_required; verification: public data absent; 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-Applied/San_AEJ-Applied_2022_148101/R/47_san_replicate.R` (213 lines)
- `AEJ-Applied/San_AEJ-Applied_2022_148101/verdict.md` (51 lines)
- `AEJ-Applied/San_AEJ-Applied_2022_148101/aeraej-47.md` (176 lines)