This paper uses a gravity framework to investigate the effects of distance as well as subnational and national borders in knowledge spillovers. Drawing on the NBER Patent Citations Database, we examine patent citations data at metropolitan level within the U.S. and the 38 largest patent-cited...

Helpman, Melitz and Rubinstein (2008) derive gravity equations to estimate effects of trade barriers on the intensive and extensive margins of trade. They exploit the frequency of zeros in aggregate bilateral trade data to identify effects on the extensive margin and to obtain controls for firm...

Gravity equations have been used for more than 50 years to estimate ex post the partial effects of trade costs on international trade flows, and the well-known - and traditionally presumed exogenous - "trade-cost elasticity" plays a central role in computing general equilibrium trade-flow and...

Gravity models of international trade have been frequently applied to estimate the impact of common (official or spoken) language on bilateral trade. This study provides a meta-analysis based on 701 language effects collected from 81 academic articles. On average, a common (official or spoken)...

This paper assesses whether the sensitivity of bilateral trade volumes to various trade cost factors is constant or varies across countries. It utilizes a random coeffcients model and analyses a cross-sectional sample of bilateral trade data for 96 countries in 2005. We expect the elasticity of...

We develop a novel two-stage methodology that allows us to study the empirical determinants of the ex post effects of past free trade agreements (FTAs) as well as obtain ex ante predictions for the effects of future FTAs. We first identify 908 unique estimates of the effects of FTAs on different...