Since European history is one of the subjects, maybe the course was European history.
The Great Depression was part of European History, causing, among other effects, the rise of the Nazis to power in Germany.
the Hawley-Smoot Tariff Act was part of European History, reducing trade between the USA and other countries including European ones, and thus making the Great Depression more depressing.
The Laffer Curve is an economic theory that applies, if valid, to European countries as well.
The list of teachers on the screen is:
ENG COMP HOLLNDR
COMPUTER SCI COWEN
UTPIAN SCY JARDIN
EURO HIST RICE
There are no characters listed with the Surnames of Hollander, McMurry, Gunner, Carlyle, Cowen, Jardin, or Rice.
There are three characters listed as teachers:
Edward Le Beau - Gym Teacher (could be Carlyle)
Del Close - English Teacher (could be Hollander)
Ben Stein - Economics Teacher (and maybe he is Rice teaching European History)
This may be a case of the right hand not knowing what the left hand is doing. There may have been a change in the courses Ferris was supposed to have during production, and someone may not have got the memo. Thus Ben Stein's character may have been listed as "Economics Teacher" in the credits and "European history teacher Rice" in Ferris' student file.
Since the room numbers seem to be clearly visible in the computer screen, checking to see if any are visible in any scene may be a good idea.
Each of Ferris's courses is four days a week, which implies that every period occupied by a class should be open one day a week except Wednesday & Friday, which perhaps is a study hall at different periods each day. Since all of the classes are on Wednesday there is no room for another one on Wednesday, the day Ferris skips school.
In any case, it seems to me that European History is the course where it would be the least odd or unlikely to discuss economic subjects, especially since 2 out of 3 are historical events.