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Adaptation of Evans, Zaytaz, and Slanta (EZS) Disclosure Method to Quarterly Census of Employment and Wages (QCEW). Shail Butani U.S Bureau of Labor Statistics (BLS) Michael Buso*, Shail Butani, David Hiles , Spencer Jobe (BLS)
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Adaptation of Evans, Zaytaz, and Slanta (EZS) Disclosure Method to Quarterly Census of Employment and Wages (QCEW) Shail Butani U.S Bureau of Labor Statistics (BLS) Michael Buso*, Shail Butani, David Hiles, Spencer Jobe (BLS) Ali Mushtaq, SantanuPramanik, Fritz Scheuren**, and Michael Yang (NORC)
Quarterly Census of Employment & Wages (QCEW) • Unemployment Insurance (U.I.) tax reports from 50 States, D.C., Puerto Rico, Virgin Islands • Virtual Census – 97% employment – 9 Million establishments – 130 Million employment – $6 Trillion wages
QCEW Data Stratification Elements • Geography – County – Metropolitan Statistical Areas (MSAs) – State • Industry – 6 digit North American Industry Classification System (NAICS) • Ownership – Private, local government, State government, Federal Government
QCEW Key Data Elements • Employment – Month 1, Month 2, Month 3 of the quarter • Total Quarterly Wages
QCEW Administrative Data Elements • Employer Identification Number (EIN) – Federal Tax ID • Unemployment Insurance (UI) number • Worksite location for multi- establishment employers • Name, addresses, phone numbers, etc.
Current Publication Cells • Most Detailed Cells County by 6 – digit Industry by Ownership • Publication Cells Most Detailed Cells and Aggregates
Current Publication Status • Sensitivity tests– P – percent rule, multiple variables • Complementary Suppression - - for many specific purposes • Total of 3.6 Million Publication Cells – 50% primary suppression (N < 3 or a dominant unit) – 10% complementary suppression
Typical Publication Table *PS = Primary Suppression *CS = Complementary Suppression • Loss of Data Utility
EZS Noise Method Developed in the 1990s by Evans, Zaytaz, and Slanta (EZS) • Magnitude variables • All responses are noise perturbed with some minimum level • Multiplicative factors, randomly selected, symmetrical • All worksites for a given company are noise perturbed either positive or negative • No complementary suppression; thus some perturbed values for sensitive cells can be derived arithmetically • No calibration to higher level aggregates
Challenges for QCEW • Employment of over 60% of the establishments is < 5 ─ Multiplicative noise factors do not work well for small employment levels since many of them round to zero ─ There are a large number of zeros (15%) in the population • Protection for small values requires some alternative to EZS.
Mixed Approach with Both Synthetic and Noise Treated Data • Synthetic for small establishments - Predicted values from statistical models, e.g., logistic regression • EZS for large establishments • Both synthetic and EZS values may be equal to reported values on a probability basis • Raking to control some key marginals • No complementary suppression – 10% more publication cells – Reduced processing time
Question for Discussion Are modeled data (synthetic or noise perturbed) considered safe and thus require no further protection?
Contact Information Shail Butani butani.shail@bls.gov 202-691-6347