According to Tim Harford, MBA students whose economics (or other) lecturer isn’t performing up to scratch should the very economics that is being failed to be taught: 

The first question is whether you think you are learning valuable skills on this MBA programme or just ”signalling” – proving that you are smart, hard-working and full of desire for a career in management consulting. If the former, then you should shop your lecturer before he denies you more opportunities to learn. Since he is teaching economics, however, I doubt you are learning anything practical. You have nothing to worry about unless the signal itself starts to look meaningless.

We then move to the next node on the decision tree. (Fancy MBA talk, no?) Does this lecturer degrade the signal your MBA is giving about what a brilliant bunch you are? As long as the external examiners are as lazy as the lecturer, your secret should be safe.

Just one thing. If you must blow the whistle, keep it all in-house. If word got around – say, to readers of the FT – that your MBA is a shambles, that really would be bad for your career prospects. So I have done you all an economic favour and left the name of your college off this letter.

I’ll leave it up to you to decide whether you can learn anything practical from economics (Harford seems inconsistent on this point). In 2003 and 2005, MBS alumni put MBS economics in the top 10 in the world according to the FT. I presume it was based on some positive learning experience.