It doesn't have to be paper style in the middle of the article, but it's good if it's present on the page (perhaps behind a button labeled "source disclosure" or similar)
I also think this increases the value I get from pieces like this, in more ways than whether or not my mind was changed. Sourcing might not influence mind changing in particular, but it'll help me if I want to dive deeper in the topic. Just yesterday I had trouble figuring out which paper was referred to by an economist piece by using google scholar queries- if there was a sources section, I'd have known instantly.
The draw of The Economist is that they are not the attention apps. The Economist could implement the most severe of editorial standards on select issues, wherein you do as I said upthread and bang the citation to a footnote at the bottom (or the last page in the print edition). The only readers who will "link out" are the people like me who you are talking to right now. Everyone else is going to see that the claim is footnoted and think "ah, of course The Economist footnoted this. It's The Economist".