I’m not at all confident these economics are true, but I imagine the argument is this: products like music, news, tv, Facebook, google search, YouTube (any ad-supported media) will now have to cost money. Their prices clearly have to go up without ads.

Next are all the businesses that will have a harder time attracting as many customers as they used to with ads- with fewer customers one can imagine they will have to raise prices as well to sustain their business.

Last, without advertising it will be much harder to start a new business. If you don’t have a highly visible store front it will be tough to gain traction no matter what sort of business you’re in. This leads to lower competition overall which also means higher prices.