Economics studies a government's monetary policy and other information using mathematical or statistical calculations (Differences). Classical and Keynesian are two completely different economic theories. Each theory takes its own approach to monetary policy, consumer behavior and government spending. There are some distinctions that separate these two theories. To begin with, classical economic theory was developed in the 1700s, during and after industrialization. Say's Law, which is the law of the market, is a principle of classical economics that says "supply makes its own demand" (classical versus Keynesian). It is supply-driven and also relies on a laissez-faire economic market. As we have learned in our previous studies, Laissez-Faire means free market, which does not depend on the government. Having little to no government allows individuals to act in their own self-interest regarding economic decisions. Government spending is not an important part in classical theory. It focuses more on consumer spending and business investment because they are the most important elements of economic growth. Classical economists believe that excessive government spending will increase the public sector and decrease the private sector where wealth is created. This theory mainly focuses on realizing long-term solutions to economic problems. Classical economists also consider how new theories and current policies will affect, negatively or positively, the free market environment (Differences). In contrast, Keynesian economic theory was presented in the 1930s, during the Great Depression, by a man named John Maynard Keynes (classical versus Keynesian). It is based on spending and aggregate demand, which makes this theory demand-driven. These economists believe that aggregate demand is influenced by public and private decisions. Public means government, private means individuals and businesses. Aggregate demand sometimes affects output, employment, and inflation. When the economy starts to slow, they rely on the government to rebuild it. Keynesian economists, similar to classical economists, also believe that the economy is made up of consumer spending, government spending, and business investment. However, Keynesian theory states that government spending can improve economic growth in the absence of consumer spending and business investment (Differences). According to Keynesian theory, wages and prices are not flexible. A static price will give a horizontal aggregate supply curve in the short run (classical and Keynesian economics). The main goal of the government stimulus was to save and create jobs almost immediately..