Microeconomics 1st Edition by Dean Karlan,Jonathan Morduch

Exercise 3

Which of the following situations are likely to involve adverse selection?
a. After receiving an emergency call during class, a professor leaves students unsupervised for the rest of the period.
b. A course has a reputation for being an easy A, even though after the term begins, students realize that it isn't.
c. A course is a requirement for physics majors but an elective for biology majors.