Abstract: | We examine retirement saving for young adults in a life cycle model. We find that optimal retirement saving is zero for liquidity-constrained young adults who anticipate significant earnings growth. With a plausible age-earnings profile for college-educated workers, retirement saving does not begin until the late 30s or early 40s. Workers facing a flat earnings profile begin saving much sooner. Participating may be optimal for younger workers facing steep earnings profiles if they anticipate switching jobs and cashing out after 1–2 years. Our results suggest that automatically enrolling workers, regardless of age, is not consistent with a life cycle model. |