The system of bail and jail in New Orleans is bad for criminal defendants, according to a new report from a nonprofit research and policy group. The city’s system also is bad business: The Vera Institute of Justice found that the cost of jailing people who can’t pay bail, fees and fines exceeds the amount of money collected.

In 2015, New Orleans spent roughly $6.4 million detaining people who were jailed only because they couldn’t pay bills imposed upon them by the city’s criminal-justice system, according to the report released Tuesday by the Vera Institute of Justice, which advocates for reducing incarceration rates. The city collected just $4.5 million from criminal defendants, most of whom are black and many of whom are poor. So the system cost the city a net total of $1.9 million — about 0.3 percent of its overall budget.

The report could add fuel to a growing outcry against local legal systems around the country that are funded in large part by costs imposed on residents — particularly those who are black and poor and including people who aren’t ultimately convicted of a crime. A 2015 U.S. Department of Justice report found that the criminal-justice system in Ferguson, Missouri, encouraged police officers and judges to maximize revenue collection in the form of fines. On Monday, the U.S. Supreme Court heard oral arguments in a case about Colorado’s stiff hurdles for defendants seeking to get their money back after their criminal convictions are reversed, and the court this month could decide to hear a similar case in Ramsey County, Minnesota. Now it’s clear that, at least in New Orleans, financially punitive justice isn’t worth it even in the coldest calculation the city might make: It doesn’t pay for itself.

“I think it is clear the system as it stands is not fair and is not working, and that the time for change is now,” Susan Guidry, a New Orleans City Council member who supports easing bond requirements for some defendants, wrote in an email in response to the report. In an email late Monday, a spokeswoman for New Orleans Mayor Mitch Landrieu said the city is working to reduce its jail population and reform its bail system, including through setting lower bail amounts for low-risk defendants.

Jailing people who can’t pay bail, fees or fines is expensive. Vera researchers found that in 2015, New Orleans residents spent 203,762 days (more than 558 person-years ) in jail for those reasons, and they estimated that detaining each person cost $31.38 per day. (The full cost of keeping someone in jail was $118.52 per day, but the researchers excluded fixed costs required to keep the jail open, such as the cost to maintain the building and to administer the jail. The researchers did take into account the potential savings on corrections officers if the jail held fewer inmates.) In total, researchers estimated, a third of people in New Orleans jails on any given night in 2015 were there because they didn’t pay bail, fines or fees.

TYPE OF CHARGE TIME IN JAIL NUMBER OF PEOPLE JAILED DUE TO BAIL AVERAGE LENGTH OF STAY (DAYS) TOTAL DAYS Felony Until trial or plea 1,275 114 144,913 Felony Until posted bail 2,208 11 24,807 Misdemeanor Until trial or plea 1,153 29 33,381 Misdemeanor Until posted bail 2,660 3 7,756 People jailed in New Orleans in 2015 for not paying bail Source: Vera Institute of Justice

The New Orleans system grew out of the need to find a way to pay for a criminal-justice system in an anti-tax political environment, according to Jon Wool, co-author of the report and director of Vera’s office in that city, which opened in 2008. The system of financing, Wool said in a telephone interview, sets in motion a vicious cycle in which more types of fees lead to more people in jail, which drives up costs and leads the city to look for new sources of revenue. “That’s a really tragic cycle and one that we won’t escape without changing how we fund the system,” Wool said.

The Vera report focuses more on the cost of New Orleans’s system to the city’s residents than on the cost to its government. In 2015, users of the criminal-justice system — as Vera calls the people arrested, detained and prosecuted in New Orleans — paid more than $16 million to the system, including the $4.5 million in bail, fees and fines, and $4.7 million to bail bond agents. “This is an enormous transfer of wealth from some of the city’s poorest residents, the vast majority of whom are black, to city government and for-profit companies,” the report says.

The system imposes many other costs on users, too: Being jailed exposes them to violence and disease in facilities, robs them of income and harms their employment prospects after release, the report says. The daily cost to people who were jailed — not counting the harm to job prospects, loss of benefits and housing, and many other factors — was $380, or 12 times the cost to the city of jailing them, according to the report.

Some advocates of a money-bail system say it encourages defendants to show up in court and deters them from committing crimes while released. Vera responds by citing research saying that the system doesn’t accomplish either goal. Advocates of money-bail systems also say it’s fairer for people accused of crimes to pay for the criminal-justice system than for all taxpayers to do so. However, some of the people paying are never convicted of a crime — some aren’t even ever charged — and some fees they pay aren’t reimbursable.

Derwyn Bunton, chief public defender for the city, said the system creates a perverse incentive for his office: If its clients plead guilty, they pay more fees, and the office gets more money. Clients sometimes tell Bunton and his colleagues, “you get paid if I lose,” he said, adding that his office doesn’t respond to the incentive. But, he said, “on paper, they’re not wrong.”

New Orleans is far from the only place with systems that impose great financial and other costs on criminal defendants and their families, but it had unique characteristics that made it well-suited for close examination. After Hurricane Katrina severely damaged the city’s jails, the city chose to build a much smaller new jail and now has far fewer cells per person than it did before the storm. Some New Orleans officials already have tried to reduce the number of people in jail, to remove bail for people accused of nonviolent crimes, and to cut costs — clashing at times with judges and the bail-bond industry. The city makes data available that allowed Vera authors to calculate revenue and cost — though it still took more than 1,000 hours of research time, they estimate. Christian Henrichson, another of the study’s authors, said New Orleans deserved credit for making the data available.

Authors of the Vera report hope that it will prompt other cities to conduct cost-benefit analyses of their systems. “We can hypothesize that other jurisdictions that rely significantly on user-generated revenues are also generating similar human and fiscal consequences,” Henrichson wrote in an email. “But we can only hypothesize, as this is the first study of its kind.”

CORRECTION (Jan. 10, 5:10 p.m.): An earlier version of this article incorrectly described the full cost of keeping someone in jail in New Orleans in 2015. The $118.52 per day figure includes the fixed costs required to keep the jail open; it does not exclude those costs.