RECHERCHE ET ANALYSE: DOCUMENTS DE TRAVAIL
Market Shares in the Post-Uruguay Round Era: A Closer Look Using Shift-Share Analysis
Shift-Share Analysis aims to break down total
change of economic indicators into various components
to identify underlying sources of growth or decline.
A key feature is that the unit of analysis (e.g. a city, a region or a
country) exists within a broader frame of reference that strongly influences
it (e.g. a
national productive system or the world economy). It is based on the
principle that total change can be disaggregated into contributing factors
and any change that can not be accounted for by these factors can be
interpreted as the “local contribution” to that total change.
This method has been subject to many refinements. Because the objectives of
this paper are both didactic and analytic, traditional Shift-Share Analysis
is applied to international trade. It uses the “constant market share”
assumption by decomposing the growth of exports into four separate
components: a global component (GLOBO) indicating changes due to overall
growth of world trade, a geographical component (GEO) indicating changes due
to the country's distribution of trading partners, a product composition
component (COMPO) indicating growth due to the mix of products exported, and
a residual term (the “local” contribution) indicating changes in
competitiveness, or performance (PERFO). The first 3 components, GLOBO,
COMPO and GEO all relate to the “expected change in trade” should trade
change proportionally. The fourth and residual component, PERFO, refers to
that part of the change in trade that “shifts away” from expected
proportional changes, hence the term “Shift-Share Analysis”.
This paper will analyse a change or “shift” in shares in trade (particularly exports) of different economies. By focusing on selected time periods and using the PERFO indicator, the method will show what industries shift away from the expected change in trade, which economies have experienced such shifts in their industries, and to which regions.
No: ERSD-2009-14
Auteurs:
Ninez Piezas-Jerbi— WTO
Coleman Nee — WTO
Date de rédaction: décembre 2009
Mots clés:
Shift-Share Analysis, International Trade.
Cotes JEL:
C49, F13, F14
Avertissement
Ce document est un document de travail et concerne donc des recherches en cours. Il témoigne de l'opinion personnelle des fonctionnaires ou des universitaires invités et est le produit de recherches professionnelles. Il n'est pas censé représenter la position ou les points de vue de l'OMC ou de ses Membres, ni la position officielle des fonctionnaires de l'OMC. Ses auteurs sont seuls responsables en cas d'erreur. Des exemplaires de ce document peuvent être obtenus auprès du Secrétariat de la division responsable, à l'adresse suivante: Division de la recherche et de l'analyse économiques, Organisation mondiale du commerce, rue de Lausanne 154, CH-1211 Genève 21, Suisse. Veuillez indiquer dans votre demande les cote et titre du document.
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