 Aggregation and the gravity equationStephen Redding and David Weinstein CEP Discussion Papers from Centre for Economic Performance, LSE Abstract: One of the most successful empirical relationships in international trade is the gravity equation, which relates bilateral trade flows between an origin and destination to bilateral trade frictions, origin characteristics, and destination characteristics. A key decision for researchers in estimating this relationship is the level of aggregation, since the gravity equation is log linear, whereas aggregation involves summing the level rather than the log level of trade flows. In this paper, we derive an exact Jensen's inequality correction term for the gravity equation in a nested constant elasticity of substitution (CES) import demand system, such that a log-linear gravity equation holds exactly for each nest of this demand system. We use this result to decompose the effect of distance on bilateral trade in the aggregate gravity equation into the contribution of a number of different terms from sectoral gravity equations. We show that changes in sectoral composition make a quantitatively relevant contribution towards the aggregate effect of distance, particularly for more disaggregated definitions of sectors. Keywords: gravity equation; trade; aggregation (search for similar items in EconPapers) Downloads: (external link) Related works: Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text Persistent link: https://EconPapers.repec.org/RePEc:cep:cepdps:dp1595 Access Statistics for this paper More papers in CEP Discussion Papers from Centre for Economic Performance, LSE |
Is your work missing from RePEc? Here is how to contribute.
Questions or problems? Check the EconPapers FAQ or send mail to .
EconPapers is hosted by the
School of Business at Örebro University.