Technological Progress, Obsolescence and Depreciation

We construct a vintage capital model A la Whelan (2002) with both exogenous embodied and disembodied technical progress, and variable utilization of each vintage. The lifetime of capital goods is endogenous and it relies on the associated maintenance costs. We study the properties of the balanced growth paths. First, we show that the lifetime of capital is an increasing (resp. decreasing) function of the rate of disembodied (resp. embodied) technical progress. Second, we show that both the use-related depreciation rate and the scrapping rate increase when embodied technical progress accelerates. However, the latter drops when disembodied technical progress accelerates while the former remains unaffected. A key feature of our model is that the age-related depreciation rate does depend on the obsolescence rate in sharp contrast to the neoclassical model.