We have begun discussing several economic concepts and theories. One economic theorist discussed was Adam Smith and his theory of the invisible hand. There are a great number of economic theorists such as Keynes, Ricardo, Ostrum, Friedman, Marx, or Marshall to name a few. For this paper, identify and research an economic theorist. Explain the theory and the impact it has or how it helps explain current economic systems' practices. Also many theorists' works have been added to or built upon by later theorists. What are these changes and do they help support current economic thought