Risk, standard deviation, and expected value: when should an individual start social security?

Abstract In choosing when to start collecting Social Security, the differences in expected net present values (NPVs) are small—but the corresponding standard deviations are not. Starting earlier is less risky. The case analyzed is single individuals in the U.S. system, but the methodology can be applied to couples and to the systems of other nations. Considering risk and return together places Social Security in the same risk/return framework as other capital investments. Behavioral, situational, and qualitative factors that often dominate decisions on when to start are linked with quantitative approaches to longevity risk and mortality risk.