What is Net National Product (NNP) ???

This is regarded as national income proper. It refers to the sum of all incomes accruing to all factors of production that are supplied by the residents of a given country over a period of time, usually a year, after deducting depreciation. Depreciation herein refers to the value of wear and tear of capital and machinery replacement after the year of use. Therefore,
GNP – Depreciation = NNP. NNP = GNP – Depreciation.
Depreciation is, in essence, that part of total productive assets which are used to replace worn-out capital in the process of creating the GNP. Hence, in the process of producing goods and services (including capital goods), a part stock of capital is used up. Depreciation is therefore the term used to denote the worn-out or used up capital. An estimated value of depreciation is deducted from the GNP to arrive at the NNP. The NNP is then the measure of net output available for consumption by the society. The NNP is usually the same as the national income at factor cost. The NNP is the usually measured at market prices, while direct taxes and indirect taxes are deducted. Hence, NNP – indirect taxes = national income.