The threat, we are told here this weekend, is existential, biological, epoch-defining. Economies will fail, civilizations will fall, and it will all happen because people aren’t having enough babies.

“The entire global financial system, the value of your money, and every asset you might buy with money is defined by leverage, which means its value depends on growth,” Kevin Dolan, a 37-year-old father of six from Virginia, tells the crowd that has gathered to hear him speak. “Every country in the developed world and most countries in the developing world face long-term population decline at a level that makes growth impossible to maintain,” Dolan says, “which means we are sitting on the bubble of all bubbles.”

Despite this grim prognosis, the mood is optimistic. It’s early December, a few weeks before Christmas, and the hundred-odd people who have flocked to Austin for the first Natal Conference are here to come up with solutions. Though relatively small, as conferences go, NatalCon has attracted attendees who are almost intensely dedicated to the cause of raising the U.S. birth rate. The broader natalist movement has been gaining momentum lately in conservative circles — where anxieties over falling birth rates have converged with fears of rising immigration — and counts Elon Musk, who has nearly a dozen children, and Hungarian prime minister Viktor Orbán among its proponents.