Data Methodology

Data Sources

PlainEmployers combines three federal government datasets into unified employer profiles, giving job seekers and researchers a multi-dimensional view of any employer's compensation, safety, and stability record:

1. DOL H-1B Labor Condition Applications

The Department of Labor Employment and Training Administration (DOL/ETA) requires employers to file Labor Condition Applications (LCAs) when sponsoring H-1B visa workers. These filings — public under the Freedom of Information Act and downloadable directly from DOL's OFLC Performance Data page — include job titles (SOC codes), prevailing and actual wage rates (sourced from the BLS Occupational Employment and Wage Statistics (OEWS) program), work locations, and the number of workers involved. PlainEmployers processes 234,000+ H-1B filings covering 290,000+ employers. This is the most comprehensive public source for employer compensation benchmarks. While the data specifically covers visa-sponsored positions, the wage information provides a reliable proxy for understanding an employer's compensation philosophy and pay structure.

2. OSHA Injury and Illness Data

The Occupational Safety and Health Administration (OSHA) collects annual injury and illness data from employers meeting federal reporting thresholds via its Injury Tracking Application (ITA). Enforcement records — citations, penalties, abatement deadlines — are published in OSHA's Enforcement Database (OIS). The key metric used is the DART rate (Days Away, Restricted, or Transferred) — the number of cases involving lost worktime per 100 full-time workers. OSHA publishes industry-average DART rates by NAICS code, enabling comparison of individual employer safety performance against the industry norm. A DART rate below the industry average indicates better-than-typical safety performance; a rate above suggests elevated workplace risk. NAICS classifications come from the U.S. Census Bureau NAICS reference.

3. WARN Act Notices

The Worker Adjustment and Retraining Notification (WARN) Act requires employers with 100+ employees to provide 60 days' advance notice before mass layoffs or plant closures. State workforce agencies publish these notices as public records, and the DOL/ETA WARN Act clearinghouse aggregates state-by-state contacts. PlainEmployers tracks 65,000+ WARN notices spanning multiple years, sourced from state workforce-agency originals (with LayoffData.com used only as an archival backstop where direct state feeds are not available). Each notice includes the employer name, location, number of affected workers, type of event (layoff, closure, or relocation), and the effective date.

Supplementary employer context

For employer-size context, PlainEmployers references the U.S. Census Bureau American Community Survey (ACS) for metro-level workforce demographics and the BLS Quarterly Census of Employment and Wages (QCEW) for industry-mean employment levels by NAICS code and county.

Data Vintage and Update Frequency

H-1B disclosure data is released quarterly by the DOL Employment and Training Administration (ETA), typically within 30 days of the quarter's end. OSHA injury and illness data is updated annually, with each release covering the prior calendar year. WARN notices are published on varying schedules by individual state workforce agencies — some states update daily while others publish monthly or quarterly. PlainEmployers refreshes each data source as new releases become available, and the database build date is displayed on the site.

Processing Pipeline

  1. Raw data files are downloaded from each federal source — DOL/ETA bulk disclosure files for H-1B, OSHA establishment-specific injury data, and state WARN databases.
  2. Employer names are normalized across all three datasets using a multi-pass process that resolves abbreviations (Inc, Corp, LLC), subsidiary names, trade names, and common spelling variants to link records to the same employer entity.
  3. H-1B wage statistics are aggregated by employer: median salary, salary range, 25th and 75th percentile wages, job title distribution, and geographic footprint across filing locations.
  4. Safety grades (A through F) are calculated by comparing each employer's DART rate against the published OSHA industry average for their specific NAICS sector. The grading scale uses standard deviation bands to assign letter grades.
  5. Stability scores reflect WARN Act history — incorporating the frequency, recency, and scale of layoff notices relative to employer size where known.
  6. Industry and state-level aggregations are pre-computed for ranking pages, enabling users to compare employers within the same sector or geography.
  7. All data is loaded into a structured SQLite database serving employer profiles, state pages, industry rankings, and search functionality.

Coverage

  • Employers: 290,000+ unique entities (via H-1B filings)
  • H-1B filings: 234,000+ Labor Condition Applications
  • WARN notices: 65,000+ mass layoff and closure notifications
  • Geographies: All 50 U.S. states and territories
  • Industries: All NAICS sectors represented in H-1B and OSHA data

Accuracy Commitment

PlainEmployers reproduces federal government data exactly as published. No subjective ratings or editorial opinions are added — grades and scores are calculated algorithmically from the underlying government data using transparent, consistent formulas. Employer name normalization is the only transformation applied, and the site clearly indicates when data is available from one, two, or all three federal sources for a given employer.

Limitations

  • H-1B salary data reflects filed wages for visa-sponsored positions only, which may not represent the full range of compensation offered to all employees at a company.
  • OSHA DART rates apply only to employers with reportable data — smaller employers or those below the reporting threshold (typically under 250 employees in most industries) may not appear in safety data.
  • Employer name normalization is imperfect — very similar names may occasionally be merged or separated incorrectly, particularly for employers with multiple subsidiaries or trade names.
  • WARN Act data relies on state agency publication, which varies in timeliness and completeness. Some states provide decades of history; others publish only recent years.
  • PlainEmployers is not affiliated with DOL, OSHA, or any government agency. The site aggregates publicly available government data for informational purposes only.