Population and Welfare: Measuring Growth when Life is Worth Living
Economic growth is typically measured in per capita terms. A long tradition in philosophy, however, suggests that social welfare may depend on the number of people as well. To illustrate how much this matters quantitatively, we decompose social welfare growth—measured in consumption-equivalent (CE) units — into contributions from rising population and rising per capita consumption. Because of diminishing marginal utility from consumption, population growth is scaled up by a value-of-life factor that empirically averages nearly 3 across countries since 1960. Population increases are therefore a major contributor to growth if one takes a total rather than per capita view. CE welfare growth around the world averages more than 6% per year since 1960 as opposed to 2% per year for consumption growth. Countries such as Mexico and South Africa rise sharply in the growth rankings, whereas China, Germany, and Japan plummet. These results are robust to incorporating richer individual preferences and endogenous fertility using time-use data from the U.S., Mexico, the Netherlands, Japan, South Africa, and South Korea.