Going into Election Day, few industries seemed in worse shape than America’s private prisons. Prison populations, which had been rising for decades, were falling. In 2014, Corrections Corporation of America, the biggest private-prison company in the US, lost its contract to run Idaho’s largest prison, after lawsuits relating to understaffing and violence that had earned the place the nickname Gladiator School. There were press exposés of shocking conditions in the industry and signs of a policy shift toward it. In April, Hillary Clinton said, “We should end private prisons.” In August, the Justice Department said that private federal prisons were less safe and less secure than government-run ones. The same month, the department announced that it would phase out the use of private prisons at the federal level. Although most of the private-prison industry operates on the state level (immigrant-detention centers are its other big business), the news sent C.C.A.’s stock down by thirty-five per cent. Donald Trump’s victory changed all that: within days, C.C.A.’s stock had jumped forty-seven per cent. His faith in privatization is no secret, and prison companies aren’t the only ones rubbing their hands. The stock price of for-profit schools has also rocketed. Still, the outlook for private prisons is particularly rosy, because many Trump policies work to their benefit. The Justice Department’s plan to phase out private prisons will likely be scrapped, and a growing bipartisan movement for prison and sentencing reform is about to run up against a President who campaigned as a defender of “law and order.” Above all, Trump’s hard-line position on immigration seems certain to fill detention centers, one of the biggest money spinners for private-prison operators. The boom in private prisons in the past two decades was part of a broader privatization trend, fuelled by a belief in the superior efficiency of the private sector. But privatizing prisons makes little economic or political sense. Some studies find private prisons to be less cost-effective than government ones, some more, and further studies suggest that any savings are likely the result of cutting corners. In a study of prisons in nine states, Chris Petrella, a lecturer at Bates College, found that private ones avoid taking sick and elderly inmates, since health care is a huge expense for prisons. They employ a younger, less well trained, and less well paid workforce and have higher inmate-to-guard ratios, all of which saves money but also makes prisons more dangerous. When you consider that the government still spends money monitoring private prisons, and that it’s stuck running the parts of the system that private companies thought were money losers, the case that private prisons save money looks shaky. Even if they did, the ethical cost would be too high. Imprisoning people is one of the weightiest things that government does, yet outsourcing imprisonment means that treatment of inmates is shaped by bottom-line considerations. This has led to understaffing, inadequate mental-health care, and, in some cases, inadequate meals. Worse, private prisons have an obvious incentive to keep people inside as long as possible. Last year, Anita Mukherjee, an assistant professor of actuarial science at the University of Wisconsin, studied Mississippi’s prison system, and found that people in private prisons received many more “prison conduct violations” than those in government-run ones. This made it harder for them to get parole, and, on average, they served two to three more months of prison time. The perversities of profit-driven prison policy don’t end there. The need for inmates leads companies, in effect, to lobby state and federal governments to maintain the current system of mass incarceration. Government-run prisons aren’t blameless here-prison-guard unions lobby for longer sentences and tougher laws-but the private companies know how to throw their weight around, and they benefit from strong local support, as they are often in rural towns without many other sources of jobs or tax revenue. Since the mid-aughts, the industry has spent tens of millions of dollars lobbying on the state and federal levels. Its successes include an Arizona law that required cops to stop suspected undocumented immigrants, major increases in spending on immigration enforcement, and the blocking of congressional efforts to ban private prisons.