I think the competition between the supermarkets was at its strongest 15 years ago when Lidl and Aldi were grabbing market share, they probably had a deflationary effect for a few years and were prepared to take lower margins in order to grab market share. Now they are mature and are increasing their margins. Inflation is also good for supermarkets. Tesco was in the doldrems a decade ago and sold retail outlets in the US and Europe, now its flying again and its share price has improved considerably although very painful if you were a Tesco shareholder a decade ago when they were fending off Lidl and Aldi. Of course Tesco is the only barometer of how supermarkets are really doing as it is the only publicly traded company. Dunnes, Musgraves Lidl and Aldi are all private. Lidl and Aldi are enormous companies though