U Roch is fantastic for economics and I’d definitely vote for U Roch over UIUC.
BC has a good program too, though, and potentially somewhat more on-campus recruiting than U Roch if you were aiming for employment in Boston or NYC right out of college. From a US perspective, it’s hard to imagine academic reasons to transfer from BC to UIUC for econ unless the real reason were unrelated, such as price or overall fit. It’s interesting that international employers would pay such close attention to a world ranking.