in foreign trade. The importance of LBD on export performance is accounted for at variouslevels of aggregation, such as LBD at the product level, LBD at the market level, and morespecifically, LBD at the market-and-product level. Using panel data covering 130 countriesand 1,003 products during the period between 1962 and 2000, this paper finds a positive butconcave relationship between foreign trade and LBD at various export levels, even aftercontrolling for country income effects, openness, and per-capita GDP growth rates. Suchrelationship is stronger and less bounded at the product-specific level. However, with moremeaningful changes, LBD at the market-specific level becomes more important than that atthe product-specific level over a longer period of time.