What exactly is a credit crunch? Why do footballers earn so much more than the rest of us?Which country is likely to be the world's leading economy in 10 years' time?Daily Telegraph economics editor Edmund Conway introduces and explains the central ideas of economics in a series of fifty essays.Beginning with an exploration of the basic theories, such as Adam Smith's 'invisible hand', and concluding with the latest research into the links between wealth and happiness, he sheds light on all the essential topics needed to understand booms and busts, bulls and bears, and the way the world really works.