The Net Domestic Product (NDP) equals the Gross Domestic Product (GDP) minus depreciation on a country's Capital (economics) goods. This is an estimate of how much the country has to spend to maintain the current GDP. If the country is not able to replace the capital stock lost through depreciation, then GDP will fall. In addition, a growing gap between GDP and NDP indicates increasing obsolescence of capital goods, while a narrowing gap would mean that the condition of capital stock in the country is improving.
