Excellence as an undergrad Econ major
Excellence demands outstanding performance, topping the class. Mastery of the subject is required. Best marks are likely, but not necessary; good marks suffice. Outstanding performance goes beyond marks. For example, a broad understanding of a discipline's application to the world, being able to apply knowledge to real problems, a thesis fit for publication (i.e., advancing domain knowledge). A good student will achieve good marks, perhaps the best marks; an excellent student will achieve something beyond marks, such as the examples listed.