The census is conducted every 10 years in the United States, but did you know it’s required by the Constitution? In Article I, Section 2, the Constitution says Congress must count the residents of the ...

Population ecology is the study of how populations — of plants, animals, and other organisms — change over time and space and interact with their environment. Populations are groups of organisms of ...

The global human population has been climbing for the past two centuries. But what is normal for all of us alive today — growing up while the world is growing rapidly — may be a blip in human history.

The number of immigrants in the United States appears to be shrinking for the first time since the 1960s — though the population of unauthorized immigrants reached a record-setting 14 million just two ...

John Wilmoth is Director, Population Division of the United Nations Department of Economic and Social Affairs (UN DESA). Clare Menozzi, Lina Bassarsky and Danan Gu are Population Officers, UN DESA.

When Andre Gay went to state prison in Pennsylvania in 1972, he was just 16 years old, sentenced to life without parole for murder and aggravated robbery. "I was a kid when I came to jail," he says, ...