Trade and Employment From Myths to Facts - International Labour ...
Trade and Employment From Myths to Facts - International Labour ...
Trade and Employment From Myths to Facts - International Labour ...
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Chapter 7: <strong>Trade</strong> diversification: Drivers <strong>and</strong> impacts<br />
Kee (2008) were the first <strong>to</strong> test empirically the importance of the reverse mechanism<br />
— from export diversification <strong>to</strong> productivity. They do so by estimating simultaneously<br />
a GDP function derived from a heterogeneous-firm model <strong>and</strong> a TFP equation where<br />
the number of export varieties (i.e. of exporting firms) is correlated with aggregate<br />
productivity through the usual selection effect. On a sample of 48 countries, they<br />
find that the doubling of product varieties observed over 1980–2000 explains a 3.3<br />
per cent cumulated increase in country-level TFP. Put differently, changes in export<br />
variety explain 1 per cent of the variation in TFP across time <strong>and</strong> countries. The explana<strong>to</strong>ry<br />
power of product variety is particularly weak in the between-country<br />
dimension (0.3 per cent). Thus, product variety does not seem <strong>to</strong> explain much of<br />
the permanent TFP differences across countries, but an increase in export diversification<br />
— for example, due <strong>to</strong> a decrease in tariffs — seems <strong>to</strong> trigger non-negligible<br />
selection effects. To recall, this selection effect means that the least efficient firms exit<br />
the domestic market when trade exp<strong>and</strong>s, raising the average productivity of remaining<br />
firms. Still, even in the within-country dimension, two-thirds of the variation in productivity<br />
is explained by fac<strong>to</strong>rs other than trade expansion.<br />
While the determinants of diversification have been studied in the previous<br />
section, we now turn <strong>to</strong> the other side of the causality <strong>and</strong> investigate the effect of<br />
export diversification on growth, starting with the well-known “natural resource curse”.<br />
7.5.2 The “natural-resource curse”<br />
The “natural resource curse” hypothesis found support with Sachs <strong>and</strong> Warner (1997)<br />
empirical findings that a large share of natural-resource exports in GDP is statistically<br />
associated, ceteris paribus, with slow growth. Since then the discussion on the existence<br />
of such a curse has been fierce. Building on Sachs <strong>and</strong> Warner (1997), Auty (2000,<br />
2001) also found a negative correlation between growth <strong>and</strong> natural-resource exports<br />
concentration. Prebisch (1950) provides a set of possible explanations for this phenomenon:<br />
deteriorating terms of trade, excess volatility, <strong>and</strong> low productivity growth.<br />
A host of other growth-inhibiting syndromes associated with natural-resource<br />
economies are discussed in Gylfason (2008). As we will see, each potential channel<br />
has been a subject of controversy; moreover, the very conjecture holds only when<br />
looking at natural-resource dependence, which is endogenous <strong>to</strong> a host of influences.<br />
Endowments of natural resources, by contrast, do not seem <strong>to</strong> correlate negatively<br />
with growth. In this section, we thus review the main arguments for <strong>and</strong> against the<br />
conjecture that concentrating on a few natural resources leads <strong>to</strong> lower growth.<br />
The notion that the relative price of primary products has a downward trend<br />
is known as the Prebisch-Singer Hypothesis. Verification of the Prebisch-Singer hypothesis<br />
was long hampered by a (surprising) lack of consistent price data for primary<br />
commodities, but Grilli <strong>and</strong> Yang (1988) constructed a reliable price index for 24 internationally<br />
traded commodities between 1900 <strong>and</strong> 1986. The index has later been<br />
updated by the IMF <strong>to</strong> 1998. The relative price of commodities, calculated as the<br />
ratio of this index <strong>to</strong> manufacturing unit-value index, indeed showed a downward<br />
log-linear trend of -0.6 per cent per year, confirming the Prebisch-Singer hypothesis.<br />
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