proportionality, which asserts that depreciation is proportional to the outstanding capital stock. All available evidence shows that …: a) the rates of depreciation and retirements vary from year to year in response to changes in conventional economic … distribution of depreciation rates by a single parameter may be characterized by simplicity and ease of use, at the same time it …

. Section 4 discusses disembodied obsolescence in more detail. Section 5 introduces new (more efficient) models of the capital …

not last too long? In this Paper we ponder the optimal rate of depreciation of physical capital, first in the Solow model … and then in a model of endogenous growth with learning-by-doing. Optimal durability and depreciation, including … obsolescence, are attained when the marginal benefit of increasing durability – and thus reducing the need for future replacement …