National Income

National Income is the total monetary value of all final goods and services produced in a country during a financial year. It's a key indicator of economic performance. There are three main methods to measure it: the Output or Production Method (summing up the net value added by all producing units), the Income Method (summing up all factor incomes like rent, wages, interest, and profit), and the Expenditure Method (summing up all final expenditure on consumption, investment, government spending, and net exports). Key concepts include Gross Domestic Product (GDP), Gross National Product (GNP), Net National Product (NNP), and Per Capita Income. Difficulties in measurement arise from issues like the black economy, non-monetized transactions, and obtaining reliable data.