There is no need to justify interest in population dynamics. But there is a pertinent need for sufficient, detailed and consistent evidence. Today, there is ample information about demographic trends for countries small, exceptionally large, and in-between. This was not always the case. Since the late 1940s, the United Nations Population Division endeavored to collect (often sparse) evidence for an increasingly complete picture known as World Population Prospects. Its evolution, through 26 revisions, is the topic of this article. It starts with the historical context, followed by brief discussions of the demographic components of change: fertility, mortality and (net) migration. Based on a reconstruction of past trends (or estimates), the Populations Division projects the population of today 235 countries or areas; the world’s population could reach between 9.4 to 12.7 billion people, with a median of 10.9 billion. The article closes with suggestions about further improvements.

Citation: Buettner, T. (2020). World Population Prospects – A Long View. Economie et Statistique / Economics and Statistics, 520‑521, 9–27.
https://doi.org/10.24187/ecostat.2020.520d.2030