Good structure is essential for good economics essay marks.Following the BLT route is a good way to show clear understanding. BLT = Because Leads to, therefore and can show how you have gone from knowledge to understanding.For example, if the question was what happens to price if supply rises. The answer - if supply goes up price goes down. Would not be as good as, because supply has increased this leads to a shift right of supply causing a movement down the demand curve therefore a fall in price. This is much better