Gross Domestic Product

GDP counts only final output, so intermediate goods are excluded to avoid double counting — the steel in a car is counted once, in the car. It measures production within a country's borders regardless of who owns the producer, which is what distinguishes it from gross national product. Its well-known limitations are that it ignores unpaid work, environmental depletion and distribution entirely, so a rising figure says nothing about who benefited. India's estimates are revised substantially between the advance, provisional and final releases, so the first number published is the least reliable.