This is plausible, though I'd be more confident in the numbers if someone could get data on total earnings over a period. Apart from salaries, those are impacted in either direction by, at least: voluntary termination and/or signing bonuses (in the plus column) and periods of unemployment between jobs (in the minus column). I don't know if those would change the totals significantly, but it's a fairly dangerous assumption to take two different groups and assume 10-year earnings are really [10 x $avg_salary], and therefore that comparing $avg_salary gives the full picture.