If you completed the prerequisites but get an error message, then: UCSC Students - email your proof of prerequisite material to the department at:
econ_ugrad_coor@ucsc.edu with the subject: Summer Econ 104 for approval to enroll; Visiting Students - email your proof of prerequisite material to the instructor for approval to enroll, Hamidreza Habibi,
hhabibi1@ucsc.edu with the subject: Summer Econ 104.