Export Diversification: What's behind the Hump?

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 (diversification of export values among active product lines and by addition of new product lines respectively) using various export concentration indices and the number of active export lines. We also look at new product introduction as an indicator of "export-entrepreneurship". We find a hump-shaped pattern of export diversification similar to what Imbs and Wacziarg (2003) found for production and employment. Diversification and subsequent re-concentration take place mostly along the extensive margin, although the intensive margin follows the same pattern. This hump-shaped pattern is consistent with the conjecture that countries travel across diversification cones, as discussed in Schott (2003, 2004) and Xiang (2007).