Description of Datasets

Abstract

We use two independent data sets in this work. • NBER trade data [1]. Compiled by the National Bureau of Economic Research, this set of bilateral trade data by commodity spans the period 1962-2000. Trade flows (in USD) are reported in product categories following 4-digit SITC rev.2 classification. This dataset is a combination of two others, spanning 1962-1983 and 1984-2000 respectively. We work with the timespan 1984-2000 to exclude any possible artifacts in the results due to changes in data collection between these two timespans. The NBER trade data introduces artificial product categories (containing 'A's and 'X's in the SITC code) to account for differences in import and export records (i.e. if country A exports to countries B,C, but A's export record deviates from (B+C)'s import records). We only focus on export data and exclude these artificial product categories. Finally, we only include 'real' countries (the dataset also lists world regions, such as Southern Asia or Oceania, etc.). This results in longitudinal trade data for 200 countries in 800 product categories over 17 years. • COMTRADE trade data [2]. The United Nations Commodity Trade Statistics Database (UN COMTRADE) publishes annual international trade statistics data by commodities and partner countries. We use data from the timespan 1990-2010. Export values (in USD) are reported in HS1992 product categories for over 170 countries (again, leaving aside world regions), amounting to roughly 5000 categories over 21 years. Let A(p, c, t) be a product indicator function for the appearance of product p in country c between year t − 1 and t, A(p, c, t) = 1 if x(p, c, t − 1) = 0 and x(p, c, t) > 0 , 0 otherwise. (1) Similarly the indicator function for a disappearance event is D(p, c, t) = 1 if x(p, c, t − 1) > 0 and x(p, c, t) = 0 , 0 otherwise. (2) Note that these definitions are only useful if there exists a data record for c at both t and t − 1. We exclude small countries from the analysis by demanding a population of at least 1.2 million people and total exports of at least 1 billion USD, leaving us with a list of 125 countries. The reported results for the SPI where computed over the timespan 1984-2000. Individual trade flows between countries are only included if they exceed 100000 USD Furthermore, appearance and disappearance events are …