There has been a lot of E-mail traffic coming in after my blog on The Greens the other day. At the heart of the matter is the fundamental difficulty people have in appreciating that there has been a fundamental shift since the 1970s in the way our monetary system operates. This shift redefines how we should think about macroeconomics and the role of a national government which issues its own currency. The defenders of The Greens economic policy clearly misunderstand this historical shift. To really get to the heart of how a modern monetary system functions you have to appreciate the difference between a convertible and non-convertible currency and a fixed versus a flexible exchange rate system. The economics that apply to convertible currency-fixed exchange rate systems bears no relation to that which applies to the fiat currency-flexible exchange rate systems that prevail in most economies today. So before you attack my macroeconomics, make sure you understand what a government can do in a modern monetary paradigm. Otherwise, you are a dinosaur and they became extinct.