Jeremy Greenwood and Per Krusell, "growth accounting with investment-specific technological progress: a discussion of two approaches" a rejoinder

The May 2007 issue of the Journal of Monetary Economics published a paper of mine entitled ‘Investment-Specific Technological Progress and Growth Accounting’ which critiqued the work of Greenwood, Hercowitz and Krusell. I argued that the Greenwood-Hercowitz-Krusell (GHK) model is a special case of a two-sector, neoclassical growth model with differing rates of technical progress in the two sectors; that a version of Jorgensonian growth accounting can be constructed for this two-sector model and hence for the GHK model; and that there is therefore a mapping between the growth accounting concepts of total factor productivity (TFP) growth in each of the two sectors, and GHK’s concepts of investment specific and neutral technological progress. The same issue of the JME published a response by Greenwood and Krusell (‘Growth Accounting with Investment-Specific Technological Progress: a Discussion of Two Approaches’). This paper is a rejoinder to theirs. It attempts to delineate both the common ground and the remaining areas of disagreement.