Three Conundrums in Measuring Poverty with a Changing Population

This note considers income distribution at two points in time where the population has also changed in some way, constructing three scenarios—population growth, population decline, and a constant population size that nevertheless churns around a constant income distribution to illustrate why standard measures of poverty, built on the intuitions of unchanging population, lead to uncomfortable or dissonant conclusions when the universe of discourse is itself subject to change.