Recent criminal justice reforms have largely focused on keeping people out of prison—reducing or eliminating sentences for those convicted of low-level offenses or offering diversion programs such as drug courts. But these efforts won’t meaningfully reduce mass incarceration until they include people serving long prison terms, many of whom were convicted of violent offenses.

Over time, people serving the longest prison terms “stack up,” contributing to the growth in the US prison population—now roughly 2.2 million, by far the highest in the world.

Research by the Urban Institute has shown that over the past few decades, people have spent more time in prison, and the longest prison terms have gotten longer. That’s because, in the 1980s and 1990s, states started handing down longer prison sentences and more life sentences while eliminating opportunities for early release through parole and “earned time” or “good time” credits.

The goal of these policies was not to rehabilitate people but to incapacitate them for as long as possible. Nearly 40 percent of people serving the longest prison terms were incarcerated before age 25, and thousands have spent more than half their lives behind bars.

More than 30 percent of people serving the longest prison terms are at least 55 years old. These older people are unlikely to reoffend if released, and they increasingly rely on health care that prisons are ill equipped to provide.

There’s no evidence that long prison terms deter crime better than short terms. But there is plenty of evidence that it shatters lives, families, and communities.

In the first episode of Urban’s new podcast, Critical Value, we look at the research on long prison terms. We interview Ryan King, an Urban Institute senior fellow, about the policies that got us here and the policies that could get us out. We also bring you the voices of people who have served long prison terms, through audio excerpts from Urban’s interactive feature “A Matter of Time.”

To solve mass incarceration, we can’t ignore people serving long prison terms. And to achieve meaningful reform, we have to look for solutions driven by research, not by retribution.

Critical Value is hosted by Justin Milner and produced by Vicky Gan and Yifan Powers. To reach the podcast team, please email criticalvalue@urban.org.