In 1980, fewer than 500,000 Americans were in prison; today, the number is 2.3 million. To put that statistic in perspective, the median incarceration rate among all countries is 125 prisoners for every 100,000 people. In England, it’s 153; Germany, 89; Japan, a mere 63. In America, it’s 743, by far the highest in the world. Include all the U.S. residents currently on probation or parole, and our country’s correctional population soars to about 7.2 million—roughly one in every 31 Americans. All told, the U.S. incarcerates nearly 25 percent of the world’s prisoners, even though it’s home to only 5 percent of the world’s inhabitants.