This argument sounds ridiculous, because it is. Canadians measure speed in kilometers per hour, not miles per hour. Moreover, many states have higher speed limits than Massachusetts. Any comparison that doesn’t account for such differences means little.
This chart is highly misleading, but for reasons invisible to most readers. EPI used different metrics to measure and adjust their pay and benefit figures for inflation. This creates completely spurious differences—just like comparing speeds calculated in kilometers and miles per hour. The EPI used the Consumer Price Index Research Series (CPI) to adjust the minimum wage and average hourly earnings for inflation. It used the Implicit Price Deflator (IPD) to adjust productivity for inflation. For methodological reasons , the CPI consistently reports more inflation than the IPD.
However, EPI used an entirely different measure of inflation, the IPD, to adjust productivity growth for inflation. Since that measure reports less inflation than the CPI, this choice causes inflation-adjusted productivity to grow faster than it would using the other measure. A substantial part of the difference in pay and productivity growth EPI depicts comes from using different metrics to adjust them for inflation.