History of WMLAD

Background: The Seattle Minimum Wage Study

In 2014, the City of Seattle passed a minimum wage ordinance requiring employers to increase workers’ pay to at least $15 per hour over the course of several years. A group of University of Washington faculty convened to study the impact of this wage ordinance on a set of outcomes (i.e. the University of Washington Minimum Wage Study, or MWS). The MWS has drawn upon Unemployment Insurance (UI) data generated by the Washington State Employment Security Department as a principal data source. The MWS used UI data on quarterly earnings and hours worked to assess the impact of Seattle’s minimum wage ordinance on hours, wages, and earnings.

Developing WMLAD

However, UI data alone cannot answer many key questions about poverty and inequality. These data do not link workers to households, meaning poverty rates cannot be calculated, and primary and secondary earners cannot be identified. In addition, for low-income households who rely on a combination of earnings and means-tested benefits, wage data can only partially describe household economic well-being. Furthermore, UI data lack information about the demographic or social characteristics of workers beyond wage level and industry. Age, race, ethnicity, gender, and nativity play large roles in labor market success, but Washington’s UI data cannot speak to these dimensions. The lack of these demographic characteristics limits the ability to evaluate distributional effects of minimum wage increases.

In response to these limitations, researchers at UW teamed up with Washington state researchers to generate a merged data resource that could supplement UI records with information from other state agencies. WMLAD resolves many of the limitations of the MWS data by merging UI data with state voting records, the drivers’ license database, public assistance and child support records, vital statistics, and select criminal justice system records.