The study looked at how young adults should save for retirement based on their future earnings. It found that young adults with limited money should not save for retirement if they expect to earn more later. College-educated workers typically start saving for retirement in their late 30s or early 40s. People with steady earnings start saving earlier. Young workers with high earning potential may benefit from saving early if they plan to change jobs quickly. The study suggests that automatically enrolling workers in retirement plans, no matter their age, doesn't match up with how people typically save over their lives.