If you have a summary measure of a group – say, life expectancy – the number could be affected by different subsets of that group. As experts discuss how the life expectancy of people in the United States is going up, they note what is driving the increase:

New mortality data from the federal government suggests that life expectancy probably hit another record high in 2025, as death rates have continued to fall since the height of the Covid-19 pandemic…

The top causes of death in the US in 2025 followed longstanding patterns: Heart disease led with nearly 695,000 deaths, followed by cancer with nearly 623,000 deaths.

Unintentional injuries, which includes drug overdoses, were the third leading cause of death. Overdose deaths are still high — about 70,000 people died from an overdose in 2025, preliminary CDC data shows — but experts say that sharp declines probably played a large role in bringing the age-adjusted death rate down in the US.

“Life expectancy is going to be affected a lot by what’s happening at younger age groups more than at older age groups,” said Mark Mather, an associate vice president at the Population Reference Bureau, a nonprofit focused on using demographic data to help improve well-being. “As we see a dramatic decline in drug overdose among younger adults, that will have a more measurable impact on life expectancy at older ages and the overall life expectancy of the population.” ​

Increasing life expectancy could involve all sorts of policies and interventions. It could involve caring for older people and the particular medical concerns they face. Helping people live better lives in their sixties and beyond is worthwhile.

Addressing the health of young people is also worthwhile. Working towards lowering infant mortality and considering other concerns before and after birth can help people live longer. Caring for children and youth can help provide them more opportunities.

Both of these approaches – helping older and younger Americans – could statistically help increase life expectancy. But as noted above, helping younger people live longer can help move the needle further as fewer deaths at younger ages mean more people will live longer. In this particular case, whatever has been done to help further a decline in drug overdoses (it would be interesting to hear more about how this was accomplished) means life expectancy, a measure for the whole population, can increase even more.