The Variety and Quality of a Nation's Trade

Working Paper: NBER ID: w8712

Authors: David Hummels; Peter J. Klenow

Abstract: Not surprisingly, big countries trade more than small countries. In this paper we use data on shipments by 110 exporters to 59 importers in 5,000 product categories to ask: how? Do big countries trade larger quantities of a common set of goods (the intensive margin), a larger set of goods (the extensive margin), or higher quality goods? We find that the extensive margin accounts for two-thirds of the greater exports of larger economies, and one-third of the greater imports of larger economies. Richer countries export more units at higher prices. These calculations are useful for distinguishing features of trade models that correspond more or less well to the data. Models with Armington national product differentiation do not feature the extensive margin, and wrongly predict that greater output will be accompanied by worse terms of trade. 'Krugman' style models with firm level product differentation fare better, but must be modified to include quality differentiation and fixed costs of trading to match all of the facts. Estimates based on these modifications imply that differences in goods' quality could be the proximate cause of about 25% of country differences in real income per worker.

Keywords: No keywords provided

JEL Codes: F43; F12; O40


Causal Claims Network Graph

Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.


Causal Claims

CauseEffect
country size (R12)extensive margin of trade (F10)
extensive margin of trade (F10)greater exports (F10)
country size (R12)greater imports (F10)
country size (R12)diversity of goods traded (F19)
rich countries (O57)export more units at higher prices (F10)
quality differentiation (L15)differences in real income per worker (J31)

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