Sectoral and aggregate technology growth in Spain

In this paper we analyze technological change in the Spanish economy by constructing adjusted Solow residuals, where the adjustment attempts to correct for the bias associated with the potential presence of imperfect competition, increasing returns, variable input utilization and, especially, sectoral reallocation of inputs across sectors. We refer to this modified Solow residual as a technology index. Sectoral reallocations and variable input utilization are key determinants of the differences between the aggregate Solow residual and the technology index resulting from the aggregation of estimated sectoral technological growth. We show that starting in the mid nineties, there has been a deceleration in the aggregate growth rate of technology which is basically due to the behaviour of the manufacturing sectors. Finally, our results imply that aggregate technology growth is less volatile than aggregate productivity as measured by the Solow residual.