This interesting article
explores the power of the supermarkets and finds a rapacious monster at our doors. It looks at their impact on Sittingbourne in Kent and summaries its findings "Forty years ago Sittingbourne High Street like so many was vibrant. Local people could buy local products and had a variety of shops to choose from. Now like so many places it is in danger of becoming a Clone Town – devoid of character with the same few shops you can find anywhere. The rise of the supermarket has a large part to play in this story. It is not too late to stem the tide but time is running out."
There are lots more reasons given in the article for retaining our individual high streets. Well worth a read.