Quality Differentiation and Trade Intermediation

Existing studies show that intermediaries can help verify or screen product quality for buyers. This paper examines this claim both theoretically and empirically in the context of international trade. We develop a heterogeneous-firm model that features vertical and horizontal differentiations of products, a coexistence of direct exporting and indirect exporting through intermediaries, and firms' investment in quality signaling. When complete contracts are not available, intermediaries underinvest in quality signaling from the perspective of the producer. For products that are more horizontally differentiated, competition is less intense and even low-quality firms export via intermediaries. These two mechanisms yield a negative (positive) cross-product relation between vertical (horizontal) differentiation and the prevalence of trade intermediation. Intermediation is more prevalent in the more (both physically and culturally) distant destinations, more so for the more vertically and horizontally differentiated products. Using detailed product-level data from China, we find supporting evidence for these predications.