Export Diversification: What's behind the Hump?
研究了156个国家19年间HS6级出口数据，发现出口多样化随经济发展呈驼峰形变化，且主要源于扩展边际。
The paper explores the evolution of export diversification patterns along the economic development path. Using a large database with 156 countries over 19 years at the HS6 level of disaggregation (4,991 product lines), we look for action at the intensive and extensive margins. We find a hump-shaped pattern of export diversification similar to what Imbs and Wacziarg (2003) found for production. Diversification and subsequent reconcentration take place mostly along the extensive margin. This hump-shaped pattern is consistent with the conjecture that countries travel across diversification cones, as discussed in Schott (2003, 2004) and Xiang (2007).