This document provides an overview of macroeconomics and the debate between free-market and Keynesian schools of thought. It discusses how Adam Smith developed ideas of free markets but John Maynard Keynes advocated government intervention to boost demand in response to the Great Depression. In the 1970s, Milton Friedman led a counter-revolution arguing excessive money supply and unions caused stagflation. Margaret Thatcher embraced free-market policies, but the 2007 crisis saw a return of Keynesian responses as the UK faced its worst recession since the 1930s.