Source: Ekaterina Jardim, Mark C. Long, Robert Plotnick, Emma van Inwegen, Jacob Vigdor, Hilary Wething, National Bureau of Economic Research, NBER Working Paper No. 23532, Issued in June 2017, Revised in May 2018
From the abstract:
This paper evaluates the wage, employment, and hours effects of the first and second phase-in of the Seattle Minimum Wage Ordinance, which raised the minimum wage from $9.47 to as much as $11 in 2015 and to as much as $13 in 2016. Using a variety of methods to analyze employment in all sectors paying below a specified real hourly wage rate, we conclude that the second wage increase to $13 reduced hours worked in low-wage jobs by 6-7 percent, while hourly wages in such jobs increased by 3 percent. Consequently, total payroll for such jobs decreased, implying that the Ordinance lowered the amount paid to workers in low-wage jobs by an average of $74 per month per job in 2016. Evidence attributes more modest effects to the first wage increase. We estimate an effect of zero when analyzing employment in the restaurant industry at all wage levels, comparable to many prior studies.