Consider the following variant sentences:
Colloquia and seminars both happen in an academic setting.
Colloquia and seminars both occur in an academic setting.
Using happen to describe ongoing events often sounds very wrong to my ear -- I usually prefer occur or some such variant, but I have no idea why that preference should be justified. Is using occur (or something like that) actually better here, or am I being overly pedantic? I'd love an explanation.