In 2021, the United States recorded its slowest population growth since at least 1900, at just 0.1 per cent as the figure above shows.

The second-lowest growth rate occurred in 1918-19, during the influenza pandemic and First World War. In absolute terms, 2021 was the first time the US population grew by less than one million people since 1937. The working-age population (aged between 15 and 64) recorded an outright decline for the third straight year in 2021.

These outcomes are partly attributable to the pandemic, which closed US borders, increased mortality and deferred births. But it also reflects longer-term trends, including record-low fertility rates. US population growth has been slowing since the early 1990s, much of which is driven by lower net international migration (NIM), the balance of migrant inflows and outflows. From a recent peak of just over one million in 2015-2016, NIM fell to just 247,000 between 2020 and 2021.

Annual per cent change in the US population, 1900-2021