Today, World Population Day, is an opportunity to reflect on the startling fact that the United States makes up just 4.4 percent of the world’s population but holds 22 percent of the world’s incarcerated population.

Individuals who advocate for criminal justice reform often cite this statistic to emphasize America’s overreliance on incarceration. Some reasons as to why so many people are incarcerated in the United States:

• Bail policies that criminalize poverty. Many people who are arrested and booked into jail cannot afford to pay the bail amount set in their case. These individuals—most of whom are charged with minor offenses, such as traffic, drug, and public order violations—must sit in jail waiting for their day in court simply because they are poor. This incarceration incurs additional costs and consequences—including user fines and fees, lost jobs and wages, and separation from family and support systems.
• The school-to-prison pipeline. Some young people under the age of 18 are arrested for status offenses that should not be considered criminal—including truancy or skipping a city curfew. Research shows that early interaction with the criminal justice system can lead to later consequences for young people, such as increased risk for criminal justice involvement as an adult.
  
• Harsh sentencing laws. Mandatory minimums and the three strikes law in California are examples of punitive sanctioning policies that resulted in many more people going to prison for longer periods of time.

While mass incarceration has deep roots in our nation’s history of slavery and racial control, the steep and dramatic rise in incarceration rates across the country began around 1970, when criminal justice policy took a punitive turn. Tough-on-crime policies included lowered rates of parole release; the introduction of mandatory minimum sentencing regimes—often for drug offenses; penalty enhancements (including three-strikes provisions); and truth-in- sentencing policies that require people convicted of crimes to serve 85 percent of their sentences in prison. Between 1970 and 2016, the number of people incarcerated in prison and jail in the U.S. grew by 575 percent. This has had a disproportionate impact on Black people, who are incarcerated at more than five times the rates of white people.

People in prison today suffer from punishing, harsh, and onerous conditions of confinement. There is extensive research and reporting detailing the inhumane and unsanitary conditions of many jails and prisons, as well as the physical, emotional, and mental torment of the people held in them. One example is the overuse of solitary confinement, where individuals are incarcerated in small spaces—typically the size of a parking space—with no human interaction, a practice that can cause and exacerbate severe mental illness. For those returning home from prison, adjusting to life in the community can be difficult, particularly given the collateral consequences of criminal conviction—such as employment discrimination. This can lead to poverty and serve as a gateway to recidivism, a person's relapse into criminal behavior, often after the person undergoes intervention for a previous crime.

Following decades of continued growth, total incarceration numbers in the United States appear to be going down. However, these rates of decline are not universal. On World Population Day, it would be remiss not to acknowledge the vulnerable population in prisons and jails across the U.S. It is imperative that we band together in efforts to combat the injustices of mass incarceration and change this population statistic.