Macroeconomics is a branch of economics dealing with the performance, structure, behavior, and decision-making of an economy as a whole. For example, using interest rates, taxes, and government spending to regulate an economy’s growth and stability. This includes regional, national, and global economies. Macroeconomists study topics such as GDP, unemployment rates, national income, price indices, output, consumption, unemployment, inflation, saving, investment, energy, international trade, and international finance.