As I drive around Southern California, I notice that Shell gas stations have some of the "higher gas prices" around. But customers of Ralphs, the supermarket chain, can use their frequent shopper points to get a 10-cent per gallon discount at Shell stations. And that discount makes the pump prices at Shell competitive with what other branded stations charge.

This got me thinking if the deal between Ralphs and Shell is artificially keeping pump prices high at the Shell stations?

If so, that means consumers who do not have Ralphs reward points to redeem could be subsidizing the lower price paid for by Ralphs customers who do redeem points at the pump.