 In the present paper we  employ the theoretical tools developed in network theory , in order to shed light on the response of world wide trade to the financial crisis of 2007. In particular, we have explored the evolution of the bipartite country-product World Trade Web  across the years 1995-2010, monitoring the behaviour of the system both before and after 2007. Remarkably, our results indicate that, from 2003 on, the abundances of a recently-defined class of bipartite motifs assume values progressively closer to the ones predicted by a null model which preserves only basic features of the observed structure, completely randomizing the rest. In other words, as 2007 approaches the World Trade Web becomes more and more compatible with the picture of a bipartite network where correlations between countries and products are progressively lost. Moreover, the trends characterizing the z-scores of the considered family of motifs suggest that the most evident modification in the structure of the world trade network can be considered as concluded in 2010, after a seemingly stationary phase of three years. In the second part of the paper, we have refined our analysis by considering subsets of nodes regarded in the literature as sharing similar economic traits: while the evolution of certain subgroups of countries and products confirms the trends highlighted by the global motifs, other groupings show a behavior compatible with our null model throughout the whole period 1995-2010, thus questioning the economic relevance traditionally assigned to these groups .
Since 2007, several contributions have tried to identify early-warning signals of the financial crisis. However, the vast majority of analyses has focused, so far, on financial systems and little theoretical work has been done on the economic counterpart. In the present paper we fill this gap and employ the theoretical tools of network theory to shed light on the response of world trade to the financial crisis of 2007 and the economic recession of 2008-2009. We have explored the evolution of the bipartite World Trade Web (WTW) across the years 1995-2010, monitoring the behaviour of the system both before and after 2007. Remarkably, our results point out the presence of early structural changes in the WTW topology: from 2003 on, the WTW becomes more and more compatible with the picture of a network where correlations between countries and products are progressively lost. Moreover, the most evident modification in the structure of the world trade network can be considered as concluded in 2010, after a seemingly stationary phase of three years. We have also refined our analysis by considering specific subsets of countries and products : according to our analysis, the most statistically significant early-warning signals are provided by the most volatile macrosectors, especially when measured on emerging economies, suggesting the latter as the most sensitive indicators of the WTW health .
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Since 2007, several contributions have tried to identify early-warning signals of the financial crisis. However, the vast majority of analyses has focused, so far, on financial systems and little theoretical work has been done on the economic counterpart.
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fill this gap and
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developed in network theory , in order
of network theory
D
wide
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2007. In particular, we
2007 and the economic recession of 2008-2009. We
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country-product
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(WTW)
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indicate that,
point out the presence of early structural changes in the WTW topology:
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abundances of a recently-defined class of bipartite motifs assume values progressively closer to the ones predicted by a null model which preserves only basic features of the observed structure, completely randomizing the rest. In other words, as 2007 approaches the World Trade Web
WTW
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bipartite
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trends characterizing the z-scores of the considered family of motifs suggest that the
R
In the second part of the paper, we have
We have also
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subsets of nodes regarded in the literature as sharing similar economic traits: while the evolution of certain subgroups of
specific subsets of
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confirms the trends highlighted by the global motifs, other groupings show a behavior compatible with our null model throughout the whole period 1995-2010, thus questioning the economic relevance traditionally assigned to these groups
: according to our analysis, the most statistically significant early-warning signals are provided by the most volatile macrosectors, especially when measured on emerging economies, suggesting the latter as the most sensitive indicators of the WTW health