This report focuses on the demand and supply analysis of Burger King, explaining the law of demand, movement along with the demand curve, change in the demand curve, law of supply, movement along with the supply curve, and change in supply curve. It also compares and contrasts emerging theories and models in 21st century contemporary economics with those of the 20th century and relates both to modern business practices. The report covers neoclassical growth theory, Keynesian economics theory, and Marx’s social economic system.