A response to Bill Martin and Robert Rowthorn

This note responds to a critique of our recent paper, "Can Intangible Investment Explain the UK Productivity Puzzle?". In that critique Martin and Rowthorn (MR) present a re-working of data on labour composition which they feel refutes an element of our argument. In this response we argue that the data are still in support of our original position. Essentially, the puzzle is that measured labour productivity has been falling, but labour quality is rising, so, at least on this measure, changes in labour quality cannot explain falling productivity.