What is it you want to do? Major in physics and philosophy and take a couple econometrics classes so you can list the software programs used for those on your resume. If you can't get the job you want with that, get a one year master's in economics from a fancy sounding school like LSE or whatever. A bachelor's in economics doesn't qualify you to do much really. At a lot of schools the economics classes are bullshit classes. You could probably get a triple major or a minor with economics with little trouble if you really want to.
But again, you won't really be qualified to do anything (besides maybe teaching) like you would with an accounting degree or an engineering degree. Or nursing, computer science, geography (GIS). If you don't go to a big name school, you could get zero interest if you do a triple major and have a high GPA. There are HR types who think that economics majors did that major because they couldn't get into the business school. A physics major is pretty impressive though. Do some internships.