---
pretty_name: WARN Act notice-type codes crosswalk - every raw state string and what it means
license: cc-by-4.0
language:
  - en
task_categories:
  - tabular-classification
  - text-classification
tags:
  - warn-act
  - data-cleaning
  - entity-resolution
  - normalization
  - crosswalk
  - codebook
  - data-dictionary
  - layoffs
  - layoff-notices
  - plant-closings
  - labor
  - labor-market
  - public-records
  - government-data
  - daily-updated
  - united-states
size_categories:
  - n<1K
configs:
  - config_name: crosswalk
    data_files: data/notice_type_crosswalk.csv
---

# WARN Act notice-type codes — the crosswalk

Every US state publishes WARN Act layoff notices with a free-text column saying
what kind of event it is. The statute recognises **two**: a *plant closing* and a
*mass layoff*. Across 48 states that column contains
**552 distinct exact strings** (531
once you fold case).

This dataset is the **crosswalk**: one row per raw string, how many notices carry
it, which states emit it, and what it normalizes to.

## The finding that matters

**521 of the 552 strings (94%) are used by exactly one state.
Only 31 are shared across states at all.**

There is no common vocabulary. `CL` means *closure* in Indiana and Wisconsin;
Illinois fills the column with `State`; five states write `WARN` — the name of the
statute — where the event type belongs. 372 strings appear on a
single notice in the entire archive.

This is why "just parse the state files" does not converge: there is nothing to
parse *toward* until someone reads all 48 vocabularies and keeps reading
them as states change their exports.

## Vocabulary by what it maps to

| maps to | distinct strings |
|---|---|
| layoff | 185 |
| closure | 147 |
| mixed (both terms present) | 23 |
| unknown (deliberately unmapped) | 197 |

`unknown` is a real category, not a failure to try. It covers blanks, strings that
name *which statute applies* rather than what happened (`State`, `WARN`, numeric
record codes), and strings that name a *cause* (`loss of contract`, `sale of
company`, `COVID-19`) rather than an event. Guessing these would manufacture
thousands of false rows that no downstream user could detect.

## The 12 most common strings

| raw value | maps to | notices | states | used by |
|---|---|---|---|---|
| *(blank)* | **unknown** | 13,759 | 29 | AK CO CT DC FL HI ID KY LA MA MN MO MT ND… |
| `Layoff Permanent` | **layoff** | 7,812 | 2 | CA TN |
| `Closure` | **closure** | 6,077 | 15 | AK AL CO KY MI MS NC NE NV NY OH PA VA WA WV |
| `Layoff` | **layoff** | 5,943 | 15 | AK AL KY MI MO MS NC NE NV NY OH PA VA WA WV |
| `State` | **unknown** | 4,845 | 1 | IL |
| `Closure Permanent` | **closure** | 4,164 | 2 | CA TN |
| `Layoff Temporary` | **layoff** | 3,657 | 2 | CA TN |
| `WARN` | **unknown** | 1,658 | 5 | AZ DE KS ME VT |
| `Plant Closing` | **closure** | 1,398 | 4 | MI NY OK PA |
| `Closing` | **closure** | 1,196 | 8 | CO CT IA MN MO PA RI WV |
| `CL` | **closure** | 862 | 2 | IN WI |
| `Mass Layoff` | **layoff** | 838 | 8 | CO IA MD MI NY OK PA WV |

## Files

- **`data/notice_type_crosswalk.csv`** — 552 rows:
  `raw_value`, `kind`, `permanence`, `reason`, `notices`, `n_states`, `states`.

Covers all **61,304** notices in the archive as of
2026-09-13; rebuilt daily in the same pipeline run as the notices
themselves, so the two can never disagree.

## Limits — read before citing

- These are **notices**, not verified job losses. A WARN notice can be amended,
  rescinded, or never carried out.
- The mapping is conservative: anything that does not clearly say closing or
  layoff is left `unknown` rather than guessed.
- `permanence` is only populated where the state says so; most states do not.
- Counts are of notices, not workers.

## Related

- [Daily US WARN notices (flagship)](https://huggingface.co/datasets/APProjects/us-warn-act-layoffs-notices-daily) — the full normalized feed
- [Plant closings vs mass layoffs](https://huggingface.co/datasets/APProjects/us-plant-closings-vs-mass-layoffs-warn-act) — this mapping applied
- [Site](https://approjects-warn-act-notices.static.hf.space) · [Source and methodology](https://github.com/APVentureEngine/warn-act-notices)

License CC-BY-4.0. Built from public state government records.