Productivity is the most important determinant of the standard of living of a group of people, a nation or a planet. Productivity in its simplest form is output per hour worked, and its recent slower growth rate is distressing. The great gains in standard of living have come from higher output per hour. That was true of the United States and Europe during the industrial revolution, and its true of Asia in recent years. Gain could, theoretically, have come from a change in distribution: more income going to workers, and less to owners of capital. Despite recent talk about inequality, changes in income distribution have not driven rising living standards over long periods of time. Rising incomes result from rising productivity.