You’ll notice that the most used metrics are ones that are measurable, objective, and easily tracked over time, even if they have serious downsides. The Dow Jones Index measures stock price but not consumer satisfaction. Unemployment data does not measure the quality of work or the level of underemployment. GPA may judge memorization and test-taking ability instead of innate intelligence. Notches do not measure a girl’s look, charm, personality, wit, or sense of humor.