this from your link.......so they MAY be part of the problem...
Interestingly supermarket discount fuel dockets may also have increased upward price volatility.
Due to the introduction of fuel dockets there may now be less pressure to discount prices, as the increasingly fewer independent retailers have little incentive and less capacity to challenge the supermarket aligned brands and their favourable wholesale pricing and support.
By extension it is also likely that the supermarket branded chains would seek to recover the costs of discounting by extending the time that prices swing upwards and by increasing grocery prices.
