[Kranar]

I don't see any proposal put forth. I see a study that is observing human behavior.

The behavior being observed is merchants increasing their prices for all consumers to accommodate a subset of consumers who use reward cards, where reward cards end up being a form of income for their holders.

The distribution of consumers who gain the most income from reward cards are those who are more wealthy. The distribution of consumers who lose the most money as a consequence of having to pay higher prices due to said reward cards are the less wealthy. The end result is a transfer of wealth from those less wealthy to those more wealthy.

That is an observation, not a proposal or a judgement. You are welcome to make a judgement or put forth a proposal from that observation but the study itself did not do so.