In his popular book "A Brief History of Time," Stephen Hawking introduces the complex world of (astro)physics to a larger audience. One of the phenomena it describes are black holes, massive stars that collapse under their own gravity and attract everything in vicinity toward the center. The book also describes the Event Horizon. This imaginary boundary close to a black hole is the point where gravity becomes so massive that even light cannot escape its grip, giving rise to the name "black hole."
This point of no return is an interesting concept that has been widely used in many other contexts. This article applies it to pension funds' balance sheets. The health of pension funds is often described by the funding ratio, which can differ dramatically across the world. Well-funded plans report ratios far above 100%, where other funds face a much more dire situation with ratios even below 30%.