The OPEC oil cartel agreed to a record output cut of two million barrels a day, the Saudi Arabian oil minister said while non-member producers also ready to slash 600,000 barrels. This is done to check the prices of oil that are at very low levels.

GDP is a measure of the total economic activity in a country. This includes the income of foreign firms in the country, income that may be remitted to the firm’s own country.

GNI is the total income earned by the citizens of a country, regardless of where that money was made.

NNI is simply GNI adjusted for depreciation of the capital resources of a country through wear and tear and damage.

Thus: NNI = GNI – depreciation.