The “S” curve relationship between export diversity and economic size of countries

► We found an S-shaped relationship between the diversity of export goods and the logarithmic GDP of all countries in the world by the highly detailed international trade data. ► This S-shaped curve is very stable during 1971-2000. ► Other diversity-related variables such as number of importers or exporters, number of import goods all exhibit S-shaped relationship with logarithmic GDP. ► The power law relationships between two diversity-related variables can be derived from the S-shaped curve. ► This paper may provide a basic empirical fact and insights for economic diversity studies.