Marginal Intra-Industry Trade: Measurement and Relevance
JEL Classification F10
Marius Brülhart
Department of Economics, Trinity College, Dublin 2, Ireland
Abstract
The presence of high and growing levels of intra-industry trade
(IIT) is commonly interpreted as a reason to expect low adjustment costs
following trade liberalisation. This paper argues that trade-induced adjustment
pressures are not directly related to the level of static IIT but to the
structure of change in trade flows. The main aspect of this structure is the
proportion of marginal intra-industry trade (MIIT). It is argued that none of
the measures of MIIT used to date are entirely satisfactory. Three complimentary
measures are thus suggested. The "A" index captures MIIT while preserving the
statistical and presentational advantages of the Grubel-Lloyd index of IIT. The
"B" index of IIT is related to MIIT as well as to sectoral trade performance,
which is particularly relevant for one-country studies. The "C" measure serves
to scale MIIT relative to other variables, such as gross trade flows or
employment. A numerical example is appended, illustrating the properties of the
various measures.
Acknowledgements
I am grateful to Prof Dermot MacAleese for valuable
comments on an earlier draft. All remaining errors are my sole responsibility.
Part of the research for this paper was financed by the Stimulation Plan for
Economic Sciences of the European Union (Contract Number SPES-CT91-0058).