Frontiers in EducationReview
How Common Is Commercial Contract Cheating in Higher Education and Is It Increasing? A Systematic Review
Across 71 samples from 65 studies, a review reports that 3.52% of students on average said they had used contract cheating, rising to 15.7% since 2014, or about 31 million students worldwide.
For teaching The review says self-reported contract cheating has risen in recent samples, but figures are probably under-reported, so treat them as rough.
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