Birthgap (2025) is a feature-length documentary that follows data scientist and demographer Stephen J. Shaw on a nine-year investigation across 24 countries to answer a single question: why are birthrates falling across nearly every society on Earth?

From the outset, the film pursues a global explanation for a pattern that appears with striking consistency across countries, cultures, and income levels. The findings that unfold over the course of the film were subsequently peer reviewed and published in a Nature Portfolio journal in 2025.

The film examines why societies separated by geography, culture, and economic conditions appear to be converging on the same outcome: ultra-low fertility. Rather than attributing the trend to isolated national factors or individual circumstances, the investigation reveals a common underlying mechanism that challenges many prevailing assumptions about choice, biology, economics, and modern life.

More than 230 people are interviewed along the way, with many sharing deeply personal experiences – alongside contributions from economists, demographic researchers, and fertility doctors. Drawing on these conversations and data analysis, Birthgap follows the process of discovery itself, as evidence accumulates and a common global explanation comes into focus.

**Earlier work-in-progress documentaries from the original Birthgap Project — Birthgap :The Prequel and Birthgap: A Childless World were selected for the New York Chelsea Film Festival in 2020 and 2021. Birthgap (2025) represents the completed feature-length documentary, filmed across 24 countries, and brings together the full arc of the investigation into the causes and consequences of global birthrate decline. It reflects the culmination of nearly a decade of research, filming, and international discourse.