There are now number of papers with a title which includes "processing trade." One can say that processing trade is now a flourishing subject matter in the research of international trade. The concept is now well established but it is enigmatic that this concept remained obscure in the 20th century.

 Papers and books with titles which include "processing trade" before 2000 are rather rare. For example, we can cite these titles:

  • Kang, C. K., & Chang, S. I. (1987). Processing trade and industrial organization. KIET, Seoul.
  •  Kalyuzhnova, Y. (1995). Outward processing trade between the European Union and the associated countries of Eastern Europe: the case of textiles and clothing. Economic Bulletin for Europe, 47, 109-127.
  •  Dapei, Z. (1997). China's Present Processing Trade and Processing Trade Policies [J]. Productivity Research, 2.
  • Eichengreen, B., & Kohl, R. (1997). The State and the External Sector in Eastern Europe: Implications for Foreign Investment and Outward Processing Trade. In Conference held by the Berkeley Roundtable on the International Economy and the Kreisky Forum for International Dialogue:" Will There Be a Unified European Economy (pp. 5-6).

 At around 2000, the titles with "processing trade" increased suddenly. For example, I can cite many papers in the year of 2000 alone.

  •  Görg, H. (2000). Fragmentation and trade: US inward processing trade in the EU. Weltwirtschaftliches Archiv, 136(3), 403-422.
  •  Fabbris, T., & Malanchini, F. (2000). Patterns of vertical specialization and European Outward Processing Trade (OPT): a comparative analysis between Mediterranean countries and CEECs. Is there real Competition.
  •  Baldone, S., Sdogati, F., & Tajoli, L. (2000). Patterns and determinants of international fragmentation of production: Evidence from outward processing trade between the EU and the countries of Central-Eastern Europe (No. 134). Queen Elizabeth House.
  •  Zhao, C. (2000). Developing overseas investments with overseas processing trade as the new starting point'. Almanac of China’s Foreign Economic Relations and Trade 2000, 45-46. 

Of course, processing trade has been discussed inside the text. For example, let me cite papers which appeared before 1990.

  •  Watanabe, T., & Komiya, R. (1958). Findings from Price Comparisons Principally Japan vs. the United States. Weltwirtschaftliches Archiv, 81-96.
  •  Murakami, M. (1968). Geographical analysis of the industrialization in Singapore. Geographical Review of Japan, 41(9), 541-570.
  •  Watanabe, S. (1972). International subcontracting, employment and skill promotion. Int'l Lab. Rev., 105, 425.
  •  Haitani, K. (1973). Japan's Trade Problem and the Yen. Asian Survey, 723-739.
  •  Yamazawa, I., & Hirata, A. (1978). Industrialization and External Relations: Comparative Analysis of Japan’s Historical Experience and Contemporary Developing Countries’ Performance. Hitotsubashi Journal of Economics, 18(2), 33-61.
  •  Nakajō, S. (1980). Japanese direct investment in Asian newly industrializaing countires and intra-firm division of labor. The Developing Economies, 18(4), 463-483.
  •  Oda, H. (1984). The Administration of Foreign Trade in the People's Republic of China. The Developing Economies, 22(2), 155-168.
  •  Grunwald, J., & Flamm, K. (1985). The global factory: Foreign assembly in international trade. Brookings Institution Press. 

My question is why the notion of "processing trade" did not become major subject matter before 2000. As you see from the list above, early papers on processing trade have been written mainly by Japanese. This can be explained by the fact that promotion of processing trade (加工貿易) has been national policy (or 国是=national principle) for Japan since many years. At the first phase of Meiji period, Japan depended heavily on the exports of Silk and Copper, but soon it started to export cotton textile which was a typical processing trade, as Japan imported cotton flower and processed and exported it. 

The story was the same for Great Britain in the time of the Industrial Revolution. It imported cotton from India, United States and others and exported cotton textile. Lionel McKenzie emphasized that "Lancashire would be unlikely to produce cotton cloth if the cotton had to be grown in England" (McKenzie 1954, p.179). Processing trade promotion is also a vital question for newly developing countries now. 

Processing trade was one of the most important forms of international trade from the beginning of modern industrial economy. It remains to be so even today. It is enigmatic why this important category of international trade remained in the background until the arrival of fragmentation and global value chain. 

Perhaps the easiest answer is to point the lack of trade theory which can treat intermediate or input goods. Despite the fact that McKenzie and Jones pointed the necessity to build a theory of intermediate or input goods, no such general theory was provided during the 20th century. In view of its importance, one may ask again why the theory of input trade was not developed much earlier. 

Do you have any good explanation? 

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