Philippe Aghion, Antonin Bergeaud, Timo Boppart, Peter Klenow, Huiyu Li, 16 August 2017

Slowing growth of total factor productivity has led some to suggest that the world is running out of ideas for innovation. This column suggests that the way output is measured is vital to assessing this, and quantifies the role of imputation in output measurement bias. By differentiating between truly ‘new’ and incumbent products, it finds missing growth in the US economy. Accounting for this missing growth will allow statistical offices to improve their methodology and more readily recognise the ready availability of new ideas, but also has implications for optimal growth and inflation targeting policies.

Francisco Buera, Ezra Oberfield, 12 June 2016

Free trade often comes hand in hand with economic growth. The opportunity for gain is relatively small, according to quantitative models that rely on standard static mechanisms. This column introduces a model to study the diffusion of ideas across countries as a means of increasing productivity, and a quantitative assessment of the role of trade in the transmission of knowledge. How much the transmission of knowledge will impact productivity depends on the openness of the trading countries, current stock of knowledge, and a diffusion parameter.