Productivity Growth
International comparisons

In comparisons of productivity growth rates, both across time and among countries, attention is often focused on the manufacturing sector, partly because of its importance for international trade. Unfortunately, comparisons based on actual productivity data are often unreliable, mainly because they fail to extract the cyclical component of productivity changes.
In Discussion Paper No. 410, Julia Darby and Research Fellow Simon Wren-Lewis adjust for these cyclical effects and also for the impact of factor substitution. They estimate employment equations that allow for both inertia in labour force adjustment and relative price effects, in which technical progress, or more generally underlying productivity, is captured by a trend term. They estimate a proxy for underlying productivity and then estimate trend productivity growth rates for each of the G7 countries over the last twenty years.
Their results suggest that most of the G7 countries suffered a decline in underlying productivity growth in the 1970s, but its extent and precise timing differed considerably. Declines were greatest for Japan, France and Germany, where the annual growth rate fell by 2-3%. The decline in Canada was a little over 1% and in the US only about 0.5%. In Italy no significant decline in trend growth appears to have occurred. The results for the UK depend critically on whether relative price effects are included in the estimated employment equation. If they are not included, underlying productivity growth falls substantially in the late 1970s, but more than recovers in the 1980s. Allowing for factor substitution, however, smoothes out these fluctuations. These developments have led to large changes in the `league table' of comparative growth rates among countries over the period.
The current relative positions among the European countries are broadly consistent with the convergence hypothesis: those countries with the lower levels of absolute productivity tend to have the higher productivity growth rates. The relatively strong growth rate for the US and the rather more uncertain recent weak growth in Japan do not fit easily, however, with the convergence hypothesis.

Julia Darby and Simon Wren-Lewis
Changing Trends in International Manufacturing Productivity

Discussion Paper No. 410, April 1990 (IM)