●Depression A very severe recession ●Cost of capital The amount forgone by holding a unit of capital for one period, including interest,depreciation,and the gain or loss from the change in the price of capital. ●Net investment The amount of investment after the replacement()of depreciated capital(一个时期的投资总额扣除现有资产的折l旧). The change in the capital stock(存量).⚫ Depression A very severe recession ⚫ Cost of capital The amount forgone by holding a unit of capital for one period, including interest, depreciation, and the gain or loss from the change in the price of capital. ⚫ Net investment The amount of investment after the replacement(扣除)of depreciated capital(一个时期的投资总额扣除现有资产的折旧). The change in the capital stock(存量).