If a high school graduate makes $6,000 more *per year* than a dropout, over a 40-year career, the total difference would be:
$6,000/year * 40 years = $240,000
Therefore, over a lifetime, a high school graduate would make $240,000 more than a high school dropout, based on this simplified model. The actual amount could vary widely depending on many other factors (salary increases over time, career changes, unemployment periods, etc.).