When plagiarism is exposed, colleagues and school leaders often close ranks around the accused. Mr. Fang said this was partly because preserving relationships trumped protecting the reputation of the institution. But the other reason, he said, is more sobering: Few academics are clean enough to point a finger at others. One result is that plagiarizers often go unpunished, which only encourages more of it, said Zeng Guoping, director of the Institute of Science Technology and Society at Tsinghua University in Beijing, which helped run the survey of 6,000 academics.

He cited the case of Chen Jin, a computer scientist who was once celebrated for having invented a sophisticated microprocessor but who, it turned out, had taken a chip made by Motorola, scratched out its name, and claimed it as his own. After Mr. Chen was showered with government largess and accolades, the exposure in 2006 was an embarrassment for the scientific establishment that backed him.

But even though Mr. Chen lost his university post, he was never prosecuted. “When people see the accused still driving their flashy cars, it sends the wrong message,” Mr. Zeng said.

The problem is not confined to the realm of science. In fact many educators say the culture of cheating takes root in high school, where the competition for slots in the country’s best colleges is unrelenting and high marks on standardized tests are the most important criterion for admission. Ghost-written essays and test questions can be bought. So, too, can a “hired gun” test taker who will assume the student’s identity for the grueling two-day college entrance exam.

Then there are the gadgets — wristwatches and pens embedded with tiny cameras — that transmit signals to collaborators on the outside who then relay back the correct answers. Even if such products are illegal, students spent $150 million last year on Internet essays and high-tech subterfuge, a fivefold increase over 2007, according to a Wuhan University study, which identified 800 Web sites offering such illicit services.

Academic deceit is not limited to high school students. In July, Centenary College, a New Jersey institution with satellite branches in China and Taiwan, shuttered its business schools in Shanghai, Beijing and Taipei after finding rampant cheating among students. Although school administrators declined to discuss the nature of the misconduct, it was serious enough to withhold degrees from each of the programs’ 400 students. Given a chance to receive their M.B.A.’s by taking another exam, all but two declined, school officials said.