Sir; When I worked in category management for a major Canadian retailer, we always operated on the premise that empty shelves in our stores would mean empty aisles, ie no customers. They would be shopping at our competitors who had the product. I struggle to understand why Sainsbury does not share that ideology. Time and time again I am faced with empty shelves and out of stocks during my frequent trips to my local Sainsbury stores. Where the retailers in the UK exceed in variety and selection, they lose on supply and availability. In a country the size of the UK, why should distribution be a concern, especially with the buying power of Tesco, Sainsbury and the like? Am I missing something here, besides a packet of my favourite sausages? Dan Evans London {{LETTERS }}