The majority of people can now expect to grow older. By 2050, 1.6 billion people will be over the age of 65. The challenge—and opportunity—that comes with increased life expectancy is ensuring that those extra years are as healthy and productive as possible. It’s an attainable goal, asserts British economist Andrew J. Scott, if the global focus shifts from the notion of an aging society to that of a longevity society, anchored in prevention, innovation, and investment.

Scott is a professor of economics at London Business School, cofounder of the Longevity Forum, and coauthor of The 100-Year Life, which has sold more than a million copies. His latest book, The Longevity Imperative: How to Build a Healthier and More Productive Society to Support Our Longer Lives (Basic Books, April 2024), outlines what needs to happen across the public, private, and social sectors to stimulate what he calls an “evergreen economy.”

As part of the McKinsey Health Institute’s (MHI’s) Conversations on Health series, Scott recently sat down with Ellen Feehan, a McKinsey partner and coleader of MHI’s healthy longevity team, to discuss the meaning of healthy longevity and why it should be top of mind—regardless of age, geography, and industry.

The following is an edited version of their conversation.