The 2008 fall in the value of sterling against the euro saw the price gap between North and South widen and shoppers cross to Northern Ireland to the detriment of businesses in the South. Coughlan asked multiple retailers to reduce their margins south of the border and provide better value to consumers in the South. Research from Forfás, concluded that only a five per cent difference in the cost of goods between North and South was justifiable. The findings highlighted retailers' larger margins in the South in relation to their operations in the North and Coughlan queried why the price differential in many identical goods was substantially in excess of 5%. Coughlan said: "I don't own a shop. The Government doesn't own a shop. It's up to Tesco, it's up to Superquinn, it's up to Aldi, it's up to Lidl; it's up to them to cut their prices. They need to ensure that that happens; they have to do something about it." When retailers continued to remain silent on the price differential, Coughlan sent in the Competition Authority to investigate supply chains in the retail sector.