E-Letter responses to:

r-articles: C. A. Hidalgo, B. Klinger, A.-L. Barabási, and R. Hausmann The Product Space Conditions the Development of Nations Science 2007; 317: 482-487 [Abstract] [Full text] [PDF]

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Published E-Letter responses:

Access to Product Space and Transformations Study Data

Cesar A. Hidalgo   (30 April 2008)

Network Modeling of Product Space and Transformations

Jiming Liu   (13 November 2007)

Access to Product Space and Transformations Study Data 30 April 2008
Cesar A. Hidalgo, Research Fellow Harvard Kennedy School Respond to this E-Letter: Re: Access to Product Space and Transformations Study Data	Thanks to J. Liu—all of these are good an interesting questions. We have made all of the data used for this study available at http://www.nd.edu/~networks/productspace. Please feel free to pursue or investigate any of them. As you might guess, there are many questions we have ourselves and the idea behind the paper can not be worked out in a single article. Thanks for your comments. Cesar A. Hidalgo Research Fellow, Harvard Kennedy School
Network Modeling of Product Space and Transformations 13 November 2007
Jiming Liu Department of Computer Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China Respond to this E-Letter: Re: Network Modeling of Product Space and Transformations	The Research Article, "The product space conditions the development of nations" by C. A. Hidalgo, B. Klinger, A.-L.Barabási, and R. Hausmann (27 July 2007, p.482) describes an interesting study in which network representations are used to visualize proximities among the products that countries export, and their evolution. On the basis of this work we would like to suggest possibilities for further investigations. Related comparative advantage (RCA): It would be interesting to incorporate in product space other factors, e.g., foreign direct (or indirect) investments (1) and the sizes of self-consumers or "prosumers" (consumers who also produce) (2). As RCA is based on the average of countries and weighted more towards a few countries (e.g., "80-20" rule), it may hide some product space and structural transformations in low-export countries. Also, RCA may be normalized by GDP or economic size. One question regarding modular structures in the product space is, how are they compared to those in random networks? Sub-scales: It would be desirable to consider product sophistication sub-scales within each classification, examining where products are exported (e.g., vehicles exported to developed countries may differ, in nature/sophistication, from those to developing countries). We may build a food-web-like network representation, where countries are nodes and import/export products are links, i.e., inter-country, directional flows of varying sophistication scales. Global/local structures, e.g., in/out-degrees of countries, and their evolution may thus be characterized. Transformations: We conjecture that certain critical economies-of-scale exist with respect to the weighted GDP per capita of countries with comparative advantage in a good (PRODYs) in different countries. Transformations can be modeled as the mean field effects of different/related types of products, where respective diffusion probabilities are derived. They are sensitive to critical time windows as well as product life cycles. Their dynamics are determined by the laws of diminishing return and increasing return. Jiming Liu Department of Computer Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong. References 1. UNCTD, World Investment Report 2006, (United Nations, New York and Geneva, 2006). 2. A. Toffler, H. Toffler, Revolutionary Wealth, (Alfred Knopf, New York, 2006).