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Global Value Chains in a Postcrisis World
hypothesis. Some countries that are part of GVCs do not show significant differences in the evolution of their elasticities, while countries less integrated in global production networks tend to do so. Although trade elasticities in general are quite volatile, the exploration of elasticity patterns does not support the hypothesis that deeper vertical integration is the driving force behind this development. There are probably more causal factors at work. We mentioned the changes in relative prices that inflated the value of primary commodities. Other factors might be the lowering of trade barriers after the conclusion of the Uruguay Round in 1995 and increasing consumer preferences for diversity as their incomes increase. New Dynamics of Trade and GDP in the Context of Global Value Chains: An Estimation with the Error Correction Model The previous sections were exploratory, and no formal assumption was made on the relationship between imports and GDP. The analysis now assumes that there is a long-run equilibrium relationship between the growth of trade and the growth of GDP, that is, that the elasticity is stable in the long run. As described at the beginning of the chapter and evidenced in figure 3.2, we expect the elasticity of trade to GDP to have increased during the 1990s because of outsourcing and offshoring, but then to have decreased afterwards, once a new steady state had been reached. The elasticity that we measure through trade and GDP data is a shortrun elasticity that reflects both the long-run equilibrium and the stochastic fluctuations that lead to volatility, such as those illustrated in the previous section on vertical integration from an I-O standpoint (sequential nature of sectoral shocks, inventory effects, and so on). We use an error correction model (ECM) to account for both the long-run equilibrium and the stochastic fluctuations, and to estimate the steady-state elasticity. Quarterly data were used from the OECD National Accounts database over the period 1961–200925 in order to have a consistent data set with timeseries for the OECD area (based on 24 OECD economies) and individual data for 30 OECD countries. The data, in constant prices, allow controlling for the changes in relative price, one of the sources of fluctuations identified in the previous sections.
Steady-State Elasticity The analysis starts with a very simple proportional relationship between trade and GDP: Mt = QYt, where Mt are imports (in volume), Yt is real GDP, and Q is the share of imports in GDP. In log form, the equation can be written: mt = q + yt with m, q, and y the natural logs of the previous variables. Adding the lagged values of