🤖 AI Summary
This study investigates how the price elasticity of Rwanda’s tungsten exports has dynamically evolved in response to institutional and market conditions following the implementation of Section 1502 of the U.S. Dodd-Frank Act. Leveraging UN Comtrade mirror data, global price indices, and exchange rates from 2009 to 2023, the analysis employs an importer fixed-effects model combined with the methodology of Nakano and Nishimura (2025) to address missing export quantity data, estimating elasticity across four distinct regulatory phases. The findings reveal, for the first time, a pronounced time-varying pattern in price elasticity under conflict mineral regulations—shifting sequentially from negative to insignificant, back to negative, and then again to insignificant—highlighting the nonlinear and complex nature of regulatory impacts on export behavior.
📝 Abstract
Section 1502 of the Dodd--Frank Act, enacted in 2010, requires U.S.-listed companies using tin, tantalum, tungsten, and gold (3TG) from the Democratic Republic of the Congo and adjoining countries to disclose information on the minerals' origins. Concerns have been raised that the regulation may have induced a de facto embargo through avoidance of sourcing from the covered region. However, how the price responsiveness of mineral exports evolved under changing institutional and market conditions remains insufficiently understood. Since tungsten production in the covered region is concentrated almost entirely in Rwanda, this study examines the price responsiveness of Rwandan tungsten exports from January 2009 to December 2023.
Because missing export quantity data prevent continuous observation of export unit values, we apply the identification approach of Nakano and Nishimura (2025), combining monthly mirror trade data from UN Comtrade with exchange rates and a world average price. An importer fixed-effects model is estimated using export value as the dependent variable, with the sample divided into four periods according to changes in the institutional and market environment.
The results reveal substantial temporal variation in price responsiveness. A statistically significant negative price response is observed in Period 1 ($η=-20.814$, $p<0.01$), disappears in Period 2 ($η=1.814$, $p>0.10$), reappears in Period 3 ($η=-5.277$, $p<0.01$), and disappears again in Period 4 ($η=0.440$, $p>0.10$). Coefficient-difference tests confirm significant changes between Periods 1 and 2 ($p=0.0021$) and between Periods 3 and 4 ($p=0.0006$). These findings suggest that the price responsiveness of Rwandan tungsten exports varied substantially over time rather than following a uniform trajectory after the regulation.