2. Ashenfelter proposed a method to estimate the causal effect of education on income based on the V1etnam draft lottery. The table below shows the average education and annual salami of two groups of men: those born on Seltember T, 1950, and those born on Se ntember 8, 1950. Average Average education, in salalj.r in 1990 1950 1950 a. Based on Ashenfelter's methodology, what is an estimate of the rate of return to a year of education [in percent terms)? (2 points)