For the past 40 years, average labor productivity and inflation-adjusted hourly compensation have risen at about the same rate, except for a passing two-year blip during the presidency of George W. Bush and during much of the presidency of Barack Obama. Per Harvard economics professor Martin Feldstein, "Two principal measurement mistakes have led some analysts to conclude that the rise in labor income has not kept up with the growth in productivity": (1) Failing to account for all forms of worker compensation. (2) Adjusting compensation and productivity for inflation by using different indexes. Many media outlets and politicians have used these flawed statistics while ignoring the data that disproves them.