I would strongly suggest that you choose the subject you enjoy most. I am a chartered accountant, who qualified with one of the Big 4 and studied English and Philosophy at University (I also had a Maths A-level). This did not limit me in any way. The majority of people I know who are accountants and studied related subjects at University found the degree quite dull and only had a very few exemptions at the start of the accounting qualification. I think economics is better respected than Business Studies, but it depends where you study and what degree you end up with. Do what you love, do well - as long as it can be justified in the interview for accounting you should be fine!