The sociology department at the University of Pennsylvania is reeling after allegations surfaced two weeks ago that a professor there committed plagiarism against a departmental colleague.

In response, 13 prominent sociologists—including two Harvard professors—wrote a letter in the Penn daily newspaper defending the accused professor, which in turn spurred the alleged victim to issue a public statement asserting that his works were not adequately cited.

The conflagration was touched off by Penn Professor of Sociology, emeritus, Harold Bershady, who sent an e-mail to all department faculty last week accusing Penn Associate Professor Kathryn J. Edin and St. Joseph’s University Assistant Professor Maria Kefalas of committing “conceptual plagiarism” in their 2005 book “Promises I Can Keep: Why Poor Women Choose Motherhood Over Marriage.”

Bershady claimed that the two scholars had taken ideas without proper acknowledgement from works by Penn’s Day Professor of Social Sciences Elijah Anderson.

Bershady circulated the allegations even though he was aware that Anderson and Edin had already resolved their differences over “Promises,” according to a statement by Paul D. Allison, the chair of Penn’s sociology department.

“Over the summer, [Anderson and Edin] repeatedly discussed the issues that separated them and they eventually resolved their differences privately,” Allison wrote in the statement. “At the time, all parties expressed full satisfaction with their agreement.”

No formal request for an inquiry was ever lodged, and neither the university nor the department considered any disciplinary action, Allison wrote.

Nonetheless, Bershady’s accusation prompted Sara McLanahan, a professor of sociology and public affairs at Princeton University, to defend Edin in a letter to the editor in the Daily Pennsylvanian, Penn’s student newspaper. McLanahan described the conceptual plagiarism charge as “absurd” and suggestive of a “fundamental misreading” of Anderson and Edin’s works.

The letter, which was published on Oct. 6, was co-signed by 12 other academics, including Harvard’s Wiener Professor of Social Policy Christopher Jencks and Professor of Sociology Mary C. Waters.

This Wednesday, Anderson ended his silence on the issue and released a response to the letter to the editor.

“I never imagined that I would be dismissed with such utter confidence by respected figures of the discipline I have devoted my scholarship and career to serving,” he wrote. “I find their letter unconvincing and disturbing.”

Anderson also wrote that Edin and Kefalas’s book “owes a strong and almost entirely unacknowledged debt to” his previous works, although he did not use the word “plagiarism.”

While “Promises I Can Keep” makes an original argument, Anderson wrote, it includes explanations, conclusions, and methods that were borrowed and not sufficiently acknowledged. The statement included a list of 22 instances where, he said, “Promises I Can Keep” paralleled his own works and did not include citations.

Robert E. Washington, a professor of sociology at Bryn Mawr College who is familiar with Edin and Anderson’s works, said that there are undeniable areas of overlap between them.

“My view is that there are some clear parallels that are striking,” he said. “In view of that, you got to acknowledge prior work.”

Washington said he found it odd that Edin did not consult with Anderson before publishing “Promises I Can Keep,” even though the book touched on Anderson’s areas of expertise.

“I find it hard to figure out how it happened that a scholar of his reputation and standing was not in fact consulted,” he said.

Washington said it is important for academics to remember that, in the past, the work of African American scholars was often ignored by white intellectuals. Anderson was the first black sociologist hired by Penn, according to the Daily Pennsylvanian.

“Given a historical context of marginalization, blacks become invisible sometimes,” Washington said.

In his statement, Anderson acknowledged that he and Edin had settled their disagreement a few months ago.

“I was satisfied by the agreement which I will continue to abide by,” he wrote.

Anderson said that he had no further comment beyond the statement, which he said is complete. Edin, Allison, and Bershady all declined to comment for this article.

Asked to respond to Anderson’s statement, Jencks declined comment too, writing in an e-mail, “I have received a request not to comment further on this matter, so that is what I am doing.”

Washington, though, said that more discussion about the standards for acknowledgement would benefit the academic community.

“I don’t think those rules are really well established yet,” he said, adding that “people are still very much in disagreement about what should be the rules in this situation.”

—Staff writer David Zhou can be reached at dzhou@fas.harvard.edu.