I had the same question around this time last year, and I was told that "comm has more short-term power, but econ has more long-term value". Comm teaches you more of the practical skills you need in a finance career, especially since it offers a finance major. Econ offers a financial markets major but it's not quite the same. Since I really enjoyed high school economics, I was considering doing actl/econ for a long time, but as someone who is interested in high finance (only going to go for accreditation if that doesn't work out), I felt like actually doing a finance degree would be better.
If you're unlike me and are really serious about becoming an actuary, I think what you choose as your double degree wouldn't matter as much. From what I've seen, Econ is more theoretical and teaches you to see society from a broader perspective which can be very interesting, but it uses so many simplifying assumptions and models that you're left wondering how much of it actually applies in the real world. If you're interested in policymaking, pick econ, but if you're more into the corporate stuff, comm may be better.
Just some thoughts. I realise now that all of this is very convoluted, but I just walked out of an Econ exam
