sectors (Sturgeon and Memedovic 2011), and extends that mapping over time through a series of concordances and correlations. This database serves as a complement to databases based on value‐added concepts, such as OECD TiVA, UNCTAD’s EORA, and IDE‐JETRO’s Asian Input‐Output tables. It complements such databases by permitting a more disaggregated view of both geography and products.

GVCs are classically characterized by lead firms which coordinate production networks. The coordination of activities required to operate dispersed production requires governance structures, which mediate the activities of multiple firms in a network with a lead firm at the center (Milberg and Winkler 2013). Some analyses of GVCs essentially view all trade as GVC‐oriented, especially those which focus on tracking global flows of value‐added through input‐output methods (Mattoo, Wang, and Wei 2013). In this view, a country which does nothing but export crude oil or metallic ores may have a high degree of GVC participation of a sort,<sup>2</sup> since these crude materials are eventually transformed into sophisticated goods or parts of other goods in some other country. However, linkages with lead firms of the sort leading to technology transfer or deeper interactions with final markets may be more likely to take place when countries are engaged in the middle or later stages of the production process.

The GVCs in vehicles, electronics, apparel, footwear and textiles are characterized by a lead‐firm network structure, and have been much studied. The similarities and differences in the organization of these five GVCs are a useful entry point into an understanding of GVCs, or as they are sometimes called “global supply chains”<sup>3</sup> (USITC 2011). They have been used to analyze the response of developing‐country GVC participants in the crisis of 2008‐2009 (Cattaneo, Gereffi, and Staritz 2010). These five sectors differ in the methods used to coordinate activity over long distances, and in the extent to which they tend to be coordinated by traditional manufacturers (motor vehicles), owners of brand names with strong research capabilities (electronics and motor vehicles), or buyers of final products working with global middlemen (apparel, footwear, textiles), in which the brand name may be associated with a designer or a retailer rather than with a manufacturer. The share of total global merchandise exports accounted for by these five GVCs has fluctuated between around 14 percent and 28 percent since 1990.<sup>4</sup>

# 1.3 Principal findings

The share of GVC trade in total merchandise imports has declined steadily, particularly from about 1998‐ 2012. Among regions, East Asia‐Pacific is the most intensively specialized in GVC exports, followed by South Asia. Sub‐Saharan Africa is the least specialized in GVC trade.

While the overall shares of the various GVC components have remained relatively constant globally, patterns of regional specialization have changed markedly. South Asia has become increasingly specialized in final apparel, driven by Bangladesh; most regions have pivoted away from this category. Final assembly

> 2 In particular, exporters of primary products experience the sort of GVC participation described as “forward linkages” in international input‐output databases.  Countries which export final goods requiring large amounts of imported intermediate goods are said to experience “backward linkages.”

> 3 The terminology in this area is not entirely standardized. “Value chains” connotes the coordination of the production of complex goods over many countries, emphasizing the role of lead firms which are usually multinational. “Supply chains” suggests a focus on the physical movement of goods necessary to make value chains happen, and can also be used to describe the transactions used in connecting global buyers and sellers of simple goods such as agricultural products.

> 4 World Bank staff calculations. The weight of classic GVC trade in total merchandise trade tends to be higher when the price of oil is low, and vice versa.

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