The article discusses how economists use Gross Domestic Product (GDP) to measure a country's national income and wealth. It also explores the challenges associated with using GDP and ways to address them. The research highlights how a country can use monetary and fiscal policies to influence national income in the short term. National income represents the total value of all goods and services produced in a country in a year. Understanding national income is crucial in macroeconomics, as it shows the connection between income, expenses, and output at a national level.