The figure in Berlin, where prostitution is legal, was higher than students surveyed in Paris (29.2 percent) and in Kiev (18.5 percent), the three cities the report looked at.
The study found some 4 percent of the 3,200 Berlin students surveyed said they had already done some form of sex work, which includes prostitution, erotic dancing and Internet shows.
The results surprised the study's authors, who said they undertook the study because student prostitution had been often reported but little was known about its relationship to education policy.
"The main motivation of students to turn to prostitution were the financial incentives, namely the high hourly wages," Eva Blumenschein, one of the study's authors and a 26-year-old student at Berlin's Humboldt University, told Reuters.
Blumenschein said recent educational reforms aimed at speeding up students' time at university may play a role in them seeking out sex work.
"It's possible that because educational reforms have increased student workloads, they have less time to earn money," she said. "Coupled with higher student fees, in this instance, leads students into prostitution."
Thirty percent of students working in the sex industry were in debt, the study found.
That compared with 18 percent of students who said they would consider sex work who were in debt.
(Reporting by Eric Kelsey, editing by Paul Casciato)
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