Arrange these moments in the study and history of population, earliest first.

1. Malthus publishes the Essay on the Principle of Population
2. Thompson sets out the sequence later called the demographic transition
3. Notestein gives the demographic transition its name
4. Spain’s total fertility rate falls below replacement level
5. World population passes eight billion on the United Nations estimate

The gap between Thompson and Notestein is worth noticing: the pattern was described from the data before anyone had a name or a causal theory for it, which is the usual order in demography. Naming it turned a regularity into a framework that was then applied, often too confidently, to countries whose transitions have not followed the European path.