Implications of ernbodied technological change for development economics

Employing a embodied technologic change model in which the time decision of scrapping old vintages of capital and adopt newer one is endogenous we show that the elasticity of substitutions among capital and labor plays a key role in determining the optimum life span of capital. In particular, for the CD case the life span of capital does not depend on the relative price of it. The estimation of the model's long-run investment function shows, for a Panel data set consisting of 125 economies for 25 years, that the price elasticity of investment is lower than one; we rejected the CD specification. Our calibration for the US suggests 0.4 for the technical elasticity of substitution. In order to get a theoretical consistent concept of aggregate capital we derive the relative price profile for a shadow second-hand market for capital. The shape of the model's theoretical price curve reproduces the empírical estimation of it. \lVe plug the calibrate version of the long-run solution of the model to a cross-section of economies data set to get the implied TFP, that is, the part of the productivity which is not explained by the model. We show that the mo dei represent a good improvement, comparing to the standard neoc!assical growth model with CD production function and disembodied technical change, in accounting the world diversity in productivity. In addition the model describes the fact that a very poor economy can experience fast growth based on capital accumulation until the point of becoming a middle income economy; from this point on it has to rely on TFP increase in order to keep growing.