Do students choose majors rationally?

And if not, what kind of errors do they make?

Students appear to stereotype majors, greatly exaggerating the likelihood that they lead to their most distinctive jobs (e.g., counselor for psychology, journalist for journalism, teacher for education). A stylized model of major choice suggests that stereotyping boosts demand for “risky” majors: ones with rare stereotypical careers and low-paying alternative jobs…The same model predicts—and the survey data confirm—that students also overestimate rare non-stereotypical careers and careers that are concentrated within particular majors. The model also generates predictions regarding role model effects, with students exaggerating the frequency of career-major combinations held by people they are personally close to.

That is all from the job market paper of John Conlon, Business Economics at Harvard University.