Furthermore, Moffitt and Gottschalk (2008), Cunha and Heckman (2007), and Gottschalk and Moffitt (1994), among others have documented significant increases in earnings volatility since the 1980s. It is therefore pertinent to consider how taking these into account might impact the previous conclusions regarding the value of education and how it has evolved over time. This is what we do in our recent work (Brown et al. 2014). We also account for the progressive tax and social security system, both of which reduce the dispersion in after-tax lifetime expected earnings across individuals.