An economics professor at Brown University suspects most of his class cheated with AI, and he has the numbers to make the case. Roberto Serrano watched his take-home midterm average hit 96 out of 100. When he switched the final to an in-person test, the average fell to 48. He has taken the story public, telling El País and Inside Higher Ed that he will not let it go.
The take-home format came out of tragedy. After a gunman killed two students on campus last December, many said they felt anxious sitting exams in a room full of people. Serrano offered take-home midterm and final papers to ease that. The irony stings: the one time in decades he relaxed the rules, much of the class cheated.
The numbers that gave it away
Serrano’s course, ECON 1170, is an advanced undergraduate economics class that usually draws a small, strong group. He had never taught more than 30 students, and once had just eight. This term, 86 signed up. The new take-home format likely drew them in.
The midterm results were, in his word, extraordinary. The class averaged 96, and 40 students scored a perfect 100. The historical average for the course sits between 65 and 80, and this exam was harder than usual. Take-home, Serrano reasoned, was a chance to push the class further, given the unlimited time.
