Okay, so we found exotic matter and can power our Alcubierre drive. It turns out though, such devices allow travel to the past. The Novikov self-consistency principle holds.

My question is, in this scenario, what would be happen with business and commerce? We have colonized a couple hundred solar systems at this point, and we have terraforming. The exotic matter was just discovered, but FTL travel quickly becomes as cheap as, say, air travel is today.

Note that you can't just hope in a time machine and go back in time. Time travel is constrained to the way FTL actually works.

My question is, how does this effect the economy?