Econ or Undecided?

After extensive research and personally talking to several admission officers, I would strongly suggest you apply with a major. I would not apply undecided. I would apply with a major that you are truly interested in. Explore what you are interested in and look at the competitiveness, future job prospects, grad school, etc… of your possible major choices. Make sure you have some experience/EC’s with those choices. Then you can decide what is best for you.

Here is a great thread about your very question.