National Income
National income refers to the total value of all goods and services produced within a country's borders in a specific time period, typically a year. It is an important economic indicator that provides insight into the overall health and performance of a country's economy.

Concepts of National Income

Gross Domestic Product (GDP)
GDP is the most widely used measure of national income. It represents the total market value of all final goods and services produced within a country during a given period. GDP can be calculated using three approaches:
- Production approach: Summing up the value added at each stage of production in different sectors of the economy.
- Expenditure approach: Summing up the total spending on consumption, investment, government expenditure, and net exports.
- Income approach: Summing up all the factor incomes earned by individuals and businesses involved in production.

Gross National Product (GNP)
GNP measures the total value of all final goods and services produced by the residents of a country, whether they are located within the country or abroad. It takes into account the income earned by residents from their assets and investments abroad, while subtracting the income earned by non-residents within the country.

Net National Product (NNP)
NNP is derived by deducting the value of depreciation from GNP. It represents the net addition to the country's stock of capital during a specific period.

National Disposable Income (NDI)
NDI is the income available to individuals and households after deducting taxes and adding transfer payments from the government. It reflects the purchasing power of the population and their ability to consume.

Per Capita Income
Per capita income is calculated by dividing the national income by the total population of a country. It provides an estimate of the average income per person and is often used to compare the standard of living between countries.

Conclusion
National income is a crucial measure that helps in assessing the economic performance and overall well-being of a country. The various concepts of national income, such as GDP, GNP, NNP, NDI, and per capita income, provide different perspectives and insights into the economic activity and income distribution within a nation. These concepts are widely used in economic analysis, policy-making, and international comparisons.