The study looked at what factors predict how much money people will earn over 20 years. They used data from surveys and tax records to see if education, job type, or short-term earnings could predict long-term earnings better. Surprisingly, they found that short-term earnings were a better predictor of long-term earnings than job type or education level. This challenges the common belief that the type of job someone has is the best indicator of how much money they will make in the long run.