Measurement of depreciation rate of technological knowledge: Technology cycle time approach

摘要

In this paper, a new method is proposed for estimating the depreciation rate of technological knowledge based on the analysis of technology cycle time (TCT). Patent citation data are used in an empirical analysis. The following features characterize the proposed TCT-based method: ⅰ) Estimation of the depreciation rate is measured by using the entire set of patents; and ⅱ) The current approach generates the sector-specific depreciation rates for individual industrial sectors. Overall, the results of empirical analysis are in accordance with expectation. The average depreciation rate (13.3 %) is rather higher than other estimates of previous research. At the same time, consistent upward trends are found over time. Regarding the sectoral variation among industries, emerging and high-tech sectors show faster pace of technical progress but at the same time higher rate of technical obsolescence, vis-a-vis traditional manufacturing sectors or light industries.