A Drop in Longevity Gains

Arolas finds that infant and child mortality are now so low that the forecasted improvements in mortality in older age groups will not be enough to sustain the previous pace of longevity gains. Clint Thayer

A new study coauthored by a UW–Madison professor finds that life expectancy gains made by high-income countries in the first half of the 20th century have slowed significantly.

“[It] appears to be a phenomenon we are unlikely to achieve again in the foreseeable future,” says Assistant Professor Héctor Pifarré i Arolas.

The study analyzed data from the Human Mortality Database for 23 high-income and low-mortality countries.

The life expectancy for an individual born in a high-income country in 1900 was an average of 62 years. For someone born just 38 years later in similar conditions, longevity had jumped to 80 years on average. But for those born between 1939 and 2000, the increase slowed.

At the beginning of the 20th century, infant mortality fell rapidly due to medical advances and other improvements in quality of life for high-income countries. This contributed significantly to the rapid increase in life expectancy. However, infant and child mortality are now so low that the forecasted improvements in mortality in older age groups will not be enough to sustain the previous pace of longevity gains.

The study provides critical insight for governments looking to anticipate the needs of their health care systems, pension planning, and social policies, as well as for individuals making decisions about retirement and long-term planning.

Published in the Spring 2026 issue