This semester, 18 courses offered at the College have enrolled more than 200 undergraduates, up from 14 last spring, according to data retrieved from the website of the Faculty of Arts and Sciences Registrar’s Office.

In keeping with recent history, Economics 10b: “Principles of Economics” has clinched the highest enrollment this semester with 662 students, the largest number of undergraduates taking the course since 2011, when the class had 689 students.

N. Gregory Mankiw, professor of Economics 10b, said that he believes his class’s high enrollment is due to the fact that students from all disciplines can benefit from studying economics.

“Harvard students know that to be an informed citizen in the world today you need to know economics,” Mankiw said, adding that the course has no cap. “It provides a very useful perspective for public policy.”

Mankiw’s two-semester introductory economics course, which has been one of the most popular courses offered in recent years, was trumped last spring by Statistics 104: “Introduction to Quantitative Methods for Economics.” While Stat 104 enjoyed an unusually high enrollment of 624 students last year, that number has been nearly halved, to 313 students this semester.

One probable reason for Stat 104’s decrease in enrollment is the introduction of Stat 102, which is geared toward pre-medical students, according to David P. Harrington, the course's professor.

“We haven’t had an introductory course for pre-meds before,” said Harrington, whose course has 115 students enrolled. “I think we drew away some of the students [from Stat 104], because there were a lot of life science and pre-medical students taking the course.”

Two General Education classes, Science of the Living Systems 19: “Nutrition and Global Health” and Culture and Belief 23: “From the Hebrew Bible to Judaism, From the Old Testament to Christianity,” were among the five highest enrolled courses this semester. Culture and Belief 23, which was last offered in the fall of 2012, has a class size of 397 undergraduates, while Science of the Living Systems 19 has 304 students enrolled.

Harvard School of Public Health professor Clifford W. Lo, who co-teaches Science of the Living Systems 19, said he is never sure what to expect with his course’s enrollments.

“The first year we had a preliminary enrollment of 80 and 250 showed up,” Lo said. He later added that pre-term planning, which predicted that approximately 150 students were interested in the course, generally does not help determine how many students will eventually take Science of the Living Systems 19.

Lo speculated that his course, which requires a final project in place of a final examination, has a reputation of being easy, but thinks that students are generally interested in global health and hopes the class will continue to attract interest.

“Someday I hope we can fit in Sanders Theatre, but right now I'm okay with Science Center B,” Lo said.

However, not all courses have experienced an increase in enrollment. Computer Science 181: “Machine Learning,” which enrolled 130 students last spring, dropped its enrollment to 68 students this semester.

Ryan P. Adams, assistant professor of Computer Science 181, said that this phenomenon may be due to the addition of several similar courses to Harvard’s course catalogue in the past year, like Computer Science 109: “Data Science,” and Statistics 183: “Learning from Big Data.”

“The students interested in these topics are now distributed over a broader range of courses than they were,” he wrote in an email to The Crimson.

—Staff writer Meg P. Bernhard can be reached at mbernhard@college.harvard.edu. Follow her on twitter @Meg_Bernhard.