What Is Macroeconomics? Explain its Limits and History.

• Macroeconomics - 

Macroeconomics is a branch of economics that studies how an overall economy—the market or other systems that operate on a large scale—behaves. Macroeconomics studies economy-wide phenomena such as inflation, price levels, rate of economic growth, national income, gross domestic product (GDP), and changes in unemployment.

Some of the key questions addressed by macroeconomics include: What causes unemployment? What causes inflation? What creates or stimulates economic growth? Macroeconomics attempts to measure how well an economy is performing, to understand what forces drive it, and to project how performance can improve.

Macroeconomics deals with the performance, structure, and behavior of the entire economy, in contrast to microeconomics, which is more focused on the choices made by individual actors in the economy (like people, households, industries, etc.).

• Limits of Macroeconomics

It is also important to understand the limitations of economic theory. Theories are often created in a vacuum and lack certain real-world details like taxation, regulation, and transaction costs. The real world is also decidedly complicated and includes matters of social preference and conscience that do not lend themselves to mathematical analysis.

Even with the limits of economic theory, it is important and worthwhile to follow the major macroeconomic indicators like GDP, inflation, and unemployment. The performance of companies, and by extension their stocks, is significantly influenced by the economic conditions in which the companies operate and the study of macroeconomic statistics can help an investor make better decisions and spot turning points.

Likewise, it can be invaluable to understand which theories are in favor and influencing a particular government administration. The underlying economic principles of a government will say much about how that government will approach taxation, regulation, government spending, and similar policies. By better understanding economics and the ramifications of economic decisions, investors can get at least a glimpse of the probable future and act accordingly with confidence.

• History of Macroeconomics

While the term "macroeconomics" is not all that old (going back to the 1940s), many of the core concepts in macroeconomics have been the focus of study for much longer. Topics like unemployment, prices, growth, and trade have concerned economists almost from the very beginning of the discipline, though their study has become much more focused and specialized through the 20th and 21st centuries. Elements of earlier work from the likes of Adam Smith and John Stuart Mill clearly addressed issues that would now be recognized as the domain of macroeconomics.

Macroeconomics, as it is in its modern form, is often defined as starting with John Maynard Keynes and the publication of his book The General Theory of Employment, Interest, and Money in 1936. Keynes offered an explanation for the fallout from the Great Depression, when goods remained unsold and workers unemployed. Keynes's theory attempted to explain why markets may not clear.

Prior to the popularization of Keynes' theories, economists did not generally differentiate between micro- and macroeconomics. The same microeconomic laws of supply and demand that operate in individual goods markets were understood to interact between individuals markets to bring the economy into a general equilibrium, as described by Leon Walras. The link between goods markets and large-scale financial variables such as price levels and interest rates was explained through the unique role that money plays in the economy as a medium of exchange by economists such as Knut Wicksell, Irving Fisher, and Ludwig von Mises.

Throughout the 20th century, Keynesian economics, as Keynes' theories became known, diverged into several other schools of thought.

• Macroeconomics vs. Microeconomics

Macroeconomics differs from microeconomics, which focuses on smaller factors that affect choices made by individuals and companies. Factors studied in both microeconomics and macroeconomics typically have an influence on one another. For example, the unemployment level in the economy as a whole has an effect on the supply of workers from which a company can hire.

A key distinction between micro- and macroeconomics is that macroeconomic aggregates can sometimes behave in ways that are very different or even the opposite of the way that analogous microeconomic variables do. For example, Keynes referenced the so-called Paradox of Thrift, which argues that while for an individual, saving money may be the key building wealth, when everyone tries to increase their savings at once it can contribute to a slowdown in the economy and less wealth in the aggregate.

Meanwhile, microeconomics looks at economic tendencies, or what can happen when individuals make certain choices. Individuals are typically classified into subgroups, such as buyers, sellers, and business owners. These actors interact with each other according to the laws of supply and demand for resources, using money and interest rates as pricing mechanisms for coordination.