National Income Concepts

National income or national product is defined as the total market value of all final goods and services produced in an economy over a period of time. There are three main concepts used to measure national income - gross national product, net national product, and national income. National income can be estimated using the product method, income method, and expenditure method. However, there are several difficulties in accurately estimating a country's national income, particularly in less developed countries, such as accounting for non-monetary transactions, production not entering the market, and lack of record keeping.