About the Washington Merged Longitudinal Administrative Data
The Washington Merged Longitudinal Administrative Data (WMLAD) is a novel data resource comprising longitudinal and geocoded administrative records from seven Washington state agencies. A single unique person identifier links all records, allowing researchers to merge information from different state agencies and follow individuals over time. All datasets cover the period 2010-2016, with some covering longer periods. Together, these records contain information on over 10 million individuals, closely approximating Census counts of working-age Washingtonians.
State Agency |
Key Information |
Time Period |
Number of Individuals |
Employment Security Department |
Earnings, hours worked, job characteristics, UI receipt |
2000-2017 |
7,699,646 workers |
Department of Social and Health Services; Health Care Authority |
Program participation, benefits received, race/ethnicity, sex, age, residential address |
2010-2017 |
4,968,258 clients |
Department of Health |
Race/ethnicity, sex, age, education, residential address |
2010-2016 |
896,558 parents |
Secretary of State |
Voting history, sex, age, residential address |
2006-2016 |
6,084,439 voters |
Department of Licensing |
Age, sex, residential address |
2005-2016 |
8,367,317 licensees |
WA State Patrol |
Arrest information |
2000-2018 |
777,416 persons arrested |
The datasets included in WMLAD touch on important economic and social indicators, with rich information on employment, social services, residential location and mobility, and demographic characteristics. State Unemployment Insurance records report quarterly, job-level hours worked and wages earned, enabling granular analysis of labor market trends. Notably, Washington is one of only four states that report data on hours worked in these records. Records from the Department of Social and Health Services and Health Care Authority indicate participation and benefits received for a number of key public assistance programs. Birth records from the Department of Health contain rich demographic information on parents of children born in Washington. Washington State Patrol records contain detailed information on arrests. Voter records from the Secretary of State track voting behavior.
The WMLAD team at UW has further enhanced these records by compiling information on residential address and demographic characteristics across sources. The team is developing novel methods to compile address data (from voter records, driver’s license records, DSHS client records, and birth records) and create longitudinal residential address histories at the Census block level. Demographic data on racial and ethnic identity, age, and sex are also compiled from multiple data sources to construct a more comprehensive demographic profile of important populations, such as Washington workers.