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title: "Product Innovation, Product Diversification, and Firm Growth: Evidence from Japan's Early Industrialization"
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[Serguey Braguinsky; Atsushi Ohyama; Tetsuji Okazaki; Chad Syverson (2021)](https://doi.org/10.1257/aer.20201656). *American Economic Review*.

**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-217.json) · [QMD](aeraej-217.qmd) · [Reproduction code](collection-code.zip)

## Source design and template applicability

num_exper_upgrades_st_cum is a cumulative count of machine-upgrade trials. The firm/semiannual fixed-effects coefficient is a dose effect, not binary adoption.

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

**13 distinct nonmissing values** in `num_exper_upgrades_st_cum`.

Observed support in the indicated source frame; missing values excluded. N=2,135; missing=0. Frame: selected_source_data. Source: /Volumes/LAL_BAK/did-cardinality-work/packages/Braguinsky_Ohyama_Okazaki_Syverson_AER_2021_145421/Final-data-and-programs/main_data.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:** verified; verification: verified; preparation: runs_with_shim. 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.

- `AER/Braguinsky_Ohyama_Okazaki_Syverson_AER_2021_145421/R/217_braguinsky_etal_figure.R` (84 lines)
- `AER/Braguinsky_Ohyama_Okazaki_Syverson_AER_2021_145421/R/217_braguinsky_etal_replicate.R` (234 lines)
- `AER/Braguinsky_Ohyama_Okazaki_Syverson_AER_2021_145421/verdict.md` (57 lines)
- `AER/Braguinsky_Ohyama_Okazaki_Syverson_AER_2021_145421/aeraej-217.md` (170 lines)