Why is labour receiving a smaller share of global income?*

Abstract The labour share of income has been on a downward trend in both advanced and emerging economies. Declining labour shares in emerging economies, though less pronounced, present an important puzzle as they contradict the predictions of classical trade theory. This paper presents a stylized mechanism to reconcile these findings, at the centre of which is routinization, that is, the automation of labour in occupations highly exposed to substitution by computer capital. We assemble a novel dataset and introduce a new measure of the exposure to routinization to analyse the drivers of falling labour shares. While technological progress and exposure to routinization explain over half the overall decline in advanced economies, in emerging markets, the globalization of trade and the accompanying capital deepening are the most significant driver, with technological progress and routinization playing a negligible role.