They touted the private model in op-eds they published in newspapers around the country, most with no mention of their funding source.
Their work didn't sit well with Alex Friedmann, managing editor of the monthly Prison Legal News and associate director of the Human Rights Defense Center, a criminal-justice advocacy group.
"Their research was funded by the very industry they were studying," said Friedmann, an ex-convict turned activist against prison privatization who filed the complaint with Temple. "It's kind of like the tobacco industry funding the Tobacco Institute, which says smoking is just fine for you."
The professors, he said, should have disclosed the funding source on their online working paper last year - and did so only after he complained.
The professors contend such disclosure wasn't required. "When it appears as a working paper, it is not final," said Hakim, who along with Blackstone is part of Temple's Center for Competitive Government. "It is just for review purposes. A few weeks after, we made the disclosure that it was partially funded by the private prison industry."
The professors said the news release on their research identified the funding source.
As for the op-eds, Hakim said at first that the newspapers must have chosen not to include it.
But he and Blackstone later said they weren't sure they had provided the information.
"We believe we did," Hakim said. "It's not that important."
Rosemary Goudreau, editorial page editor of the Sun-Sentinel in Fort Lauderdale, Fla., said she no longer had the professors' original version, but said if they had included the funding source, the paper would have noted it "to help people understand where they were coming from."
The State Journal in Frankfort, Ky., was one paper that included the funding source.
"When it was submitted, I point-blank asked, 'Are these guys receiving funding for their research from the industry?' " editor Dan Liebman said. He said he wouldn't print the piece without that disclosure.
The ethics of research funding is thorny for academia, where money can be difficult to raise other than from the industry itself. The American Economic Association adopted a policy in January directing members to disclose the sources of their research funding in journal articles and urging them to do the same in other publications, including op-eds.
Several experts said researchers should disclose their funding source at every step once the research becomes public, whether in a working paper posted online or a final version in a journal. "It's quite disingenuous to say the funding source shouldn't have gone on the working paper," said Cary Nelson, former president of the American Association of University Professors and an expert on faculty conflict of interest. In the online world, he said, "what's the difference between a working paper and the final version?"
Nelson, also a professor emeritus of English at the University of Illinois, said the professors should have insisted the funding be disclosed in any op-ed.
"As someone that has published a lot of op-eds," he said, "if you say firmly, 'My professional credibility and the regulations of my university require that I disclose my funding, and I cannot go forward unless I do,' the publications will work that out with you."
Companies often are willing to pay for the prestige of "objective" university research to back their contentions, Nelson said.
"It's that objectivity we need to protect," he said.
Marybeth Gasman, a University of Pennsylvania education professor, said it was unethical for Hakim and Blackstone not to be up-front about funding in prison-related research, given "that their research is about the very organizations that are funding them and they are writing opinion pieces where they are advocating certain positions."
Arthur L. Caplan, bioethics professor and director of the division of medical ethics at New York University's Langone Medical Center, said professors should ideally obtain funding from multiple sources.
"If it is sole-source funding," said Caplan, formerly of Penn, "it should be from a not-for-profit."
Neither Hakim nor Blackstone would say how much funding they received from the private prison groups.
Both said they had no stock or financial interest in the private prison industry. Temple policy requires researchers to disclose significant financial interests in an entity with which they are involved and sets limitations on conflicts of interest.
Temple expects to complete its investigation by the end of the summer, spokesman Ray Betzner said. University officials declined to comment on possible sanctions the professors could face if the investigation found fault with their actions.
Hakim and Blackstone, who have been research partners for 20 years, said they weren't worried because they did nothing wrong.
"We're academics," Blackstone said. "We're trying to be as candid as possible."
After speaking with an Inquirer reporter, the professors contacted the Corrections Corporation of America - the nation's largest private corrections company and one of their funders - and asked it to contact The Inquirer. Steve Owen, spokesman for the Nashville corporation, said Friedmann, of the Human Rights Defense Center, was an "anti-privatization activist" only interested in "silencing this research."
"It's very telling that not one person has yet to say one thing critical about the validity of the research and the findings," he said.
Friedmann takes issue with the efficacy of private prisons based on his personal experience. For armed robbery, assault, attempted murder, and attempted aggravated robbery, he spent 10 years in prison, six of them in a Clifton, Tenn., private facility run by Owen's corporation and four in a public prison.
Released in 1999 - and disturbed by what he called inadequate staffing and lack of supplies at the private prison - he became an activist and even bought stock in the corporation so he could ask questions at meetings.
Friedmann was also critical of Temple. "The university," he said, "did a poor job of policing this study."