Seattle's enactment of a $15 minimum wage is a dramatic increase for the city. (Or, it will be, once it is fully enacted in 2017.) (And if it survives legal challenges.) But as is often pointed out when a minimum wage increase is improved, minimum wages rarely keep up with the devaluation of the dollar.
We decided to visualize that. Using conversion metrics created by Oregon State University and data on the minimum wage from the Department of Labor, here's how the federal minimum wage has evolved over time, in nominal dollars (what the wage was set to that year) and in 2014 dollars.
Every so often, the minimum wage goes up — but it hasn't kept up with the value of the dollar.
The picture doesn't look much different when you do the same calculation for the states. Watch the jump from 2013 to 1968 when the animation below loops.
(We had to make some editorial decisions on the values here. If a state didn't have a minimum wage, for example, we used the federal limit. If it had a range of minimum wages, we used the highest value.)
The highest minimum wage in 2014 dollars was Alaska's $2.10 in 1968 — over $14 today. Or, in other words, slightly less than Seattle residents may see in three years' time. Assuming the dollar's value doesn't change too much.