By Tiana Herring / Prison Policy Initiative

After skyrocketing for decades, overall incarceration rates have finally been on a slow decline since 2008. But a closer look at the data reveals a major exception: women. From 2009 to 2018, the number of women in city and county jails increased by 23% — a rise that effectively cancelled out more than 40% of the simultaneous 7.5% decrease in the men’s jail population. Meanwhile, reductions in state and federal prison populations have mostly affected men.

Women make up about 10% of people in jails and prisons. This means that patterns unique to women’s incarceration are easily obscured when we focus exclusively on the larger, overall incarcerated population. And when we overlook incarcerated women as a unique group, we also fail to address the additional challenges they face — including different health care needs and a greater likelihood of being a primary caretaker of young children — that make their growing numbers all the more alarming.

Since public health research shows that women are also affected in unique ways by the opioid crisis, we decided to see whether drug enforcement trends and substance abuse could be contributing to the rising number of women behind bars.

Over the past 35 years, total arrests have risen 15% for women, while decreasing 40% for men. The increase among women is largely driven by drugs: During that period, drug related arrests increased nearly 190% for women, compared to 34% for men.