Macroeconomics is the study of economy-wide output, employment, inflation, and related indicators.
It examines aggregates such as national production, the unemployment rate, the general price level, economic growth, and business cycles. Macroeconomists study how households, firms, governments, and financial institutions interact across the entire economy.
The field developed into its modern form during the 20th century, especially after the Great Depression. John Maynard Keynes’s 1936 book, The General Theory of Employment, Interest and Money, strongly influenced analysis of aggregate demand and economic fluctuations.
Macroeconomics differs from microeconomics, which focuses on individual consumers, firms, and markets. The two fields overlap: economy-wide outcomes arise from many individual decisions, while national conditions influence those decisions. Macroeconomic policy commonly includes monetary policy conducted by a central bank and fiscal policy involving government spending and taxation.