Lots of students tend to believe they are interrelated and this is how I myself thought too long ago. And the answer is they are entirely different from one another. BBA is a business administration course which means managing people and resources required to run a business/ company. Economics is a course that governs the business. To be simple, it tells you how efficiently the business runs, how efficiently the people of the company are put to use and how efficiently the resources of the company are put to use to help run the business. For example, you own a company that sells some food products. As the company owner you will be responsible for employing persons to manufacture the product, handle finance, do marketing of the product and finally sell the product at the stores. So you are only bothered to run the business with the resources you have and nothing beyond that. But there might be many reasons why certain business gets affected at some time, and to understand the reasons 'Economics' subject comes in.

As a Economist you will understand why customers dont prefer a product during particular period and why they prefer buying a product at other seasons. Good example is, the job of an Economist is to understand why juices and ice-creams sell in surplus during summer. We all know that these products are preferred in summer than in winter but an Economist thinks beyond this. He goes to the extent to understand how the sales, country's economy gets affected in winter when these products doesn't get sold. They also act as an advisor to companies to advise what all a company could do to make money even in winter. Another example is the rising costs of petrol. As an Economist, they will analyse if the rising costs of petrol has affected people using vehicles for transportation. They will try to find if people are still buying petrol though the cost is raised or if they have cut down on buying petrol. If they have cut down, then what other modes of transportation are the people using? Are they dependent on public transports, and if the dependence on public transports is increased, how much the government makes revenue out of this? If they started using bicycles, are the bicycles company benefited with increased bicycle sales because of this raise in petrol price? Simple, an Economist thinks how all a business gets affected and who are the other benefactors due to this. Where in a business person thinks how all he can function and improve his business by utilizing all that he has.

If you would like to manage people, influence people then BBA is the right choice for you. If you would like to advice people and organisations during bad times then Economics is right for you. Hope you are clear now. Good luck.