Dr. Joseph, I am a little confused with what would be a better choice in my case -
I am a Finance major currently, but I would love to add another major (double major) as either Marketing or Business Economics.
My dad has his own business of diamonds, and in the future I will definitely run his business. Therefore, Marketing or Business Economics, which would be a better option?
Marketing since most businesses now need sells. I would also recommend that you obtain your gemology or GIA certification. http://www.gia.edu/
is a good place to look this up. Most of my friends in your father's business are making as much with appraisal of gems as they are selling. Thank you for checking on this, and hope this website helps your journey.