I was wondering which of these two colleges is easier to get into, since I plan to apply ED.
I eventually want to work on Wall Street.
From what I’ve seen AEM seems to be under CALS, and thus has a higher acceptance rate compared to CAS.
Is this true? Or should I stick to applying as an econ major to CAS?
AEM is the most selective major within CALS (and one of the most selective at Cornell), with a 7% acceptance rate. It’s a great program, though, so I definitely don’t want to discourage you from applying.
Are students from the statutory colleges allowed to dorm with students from the endowed colleges?
The reason it is harder to get into AEM is because many athletes are place in AEM. Most non-hook EDers for AEM are deferred. You don’t need to be in AEM to take classes there, but their students have the first priority. My daughter was a CAS student. She took few courses there and was even a TA there. She did end up working in WS. All freshmen live in North Campus. They do not put students together by school. People do no differentiate between schools, especially not statutory vs endowed. You’ll find CAS students making fun of Hotellies, but it is all fun (Hotel school courses are perceived to be easier, and Hotellies are better looking. 
)
AEM only takes 100 incoming freshmen.