Macroeconomics is a sub-field of economics that examines the behavior of the economy as a whole, once all of the individual economic decisions of companies and industries have been summed. Economy-wide phenomena considered by macroeconomics include Gross Domestic Product (GDP) and how it is affected by changes in unemployment, national income, rate of growth, and price levels.
In contrast, microeconomics is the study of the economic behaviour and decision-making of individual consumers, firms, and industries.
Macroeconomics can be used to analyze how to influence government policy goals such as economic growth, price stability, full employment and the attainment of a sustainable balance of payments.
Macroeconomics is sometimes used to refer to a general approach to economic reasoning, which includes long term strategies and rational expectations in aggregate behavior.
Until the 1930s most economic analysis did not separate out individual economics behavior from aggregate behavior. With the Great Depression of the 1930s, suffered throughout the developed world at the time, and the development of the concept of national income and product statistics, the field of macroeconomics began to expand. Particularly influential were the ideas of John Maynard Keynes, who formulated theories to try to explain the Great Depression. Before that time, comprehensive national accounts, as we know them today, did not exist .
One of the challenges of economics has been a struggle to reconcile macroeconomic and microeconomic models.
