Book excerpt: In a series of 50 accessible essays, Ed Conway introduces and explains the essential economic concepts needed to understand booms and busts, bulls and bears, and how economics influences every aspect of our lives, whether buying a house or what you ate for breakfast this morning. From Adam Smith's invisible hand to supply and demand, stocks and shares to communism, 50 Economics Ideas You Really Need to Know is a complete introduction to the most important economics concepts in history.