Jaerim Choi

Summary Instrumental variable (IV) methods for regression are well established. More recently, methods have been developed for statistical inference when the instruments are weakly correlated with the endogenous regressor, so that estimators are biased and no longer asymptotically normally distributed. This paper extends such inference to the case where two separate samples are used to implement instrumental variables estimation. We also relax the restrictive assumptions of homoskedastic error s

Abstract We evaluate the direct impact of China trade shock on the Korean labour market following the approach of Acemoglu, Autor, Dorn, Hanson, and Price ( Journal of Labor Economics , 2016, 34, S1). Using firm‐ and industry‐level data for the period 1993–2013, our direct estimates imply that the net employment effect of the China shock in the manufacturing sector is the creation of 0.52 million jobs. The positive impact is mostly driven by China's rising demand for intermediate inputs and capi

Abstract This paper provides evidence on the effects of US and Chinese trade policies on the 2020 US presidential election. In response to a series of US tariffs imposed on Chinese goods, China imposed retaliatory tariffs, especially on US agricultural products, which largely affected Republican‐leaning counties. The US government then subsidized US farmers by providing direct payments through the Market Facilitation Program (MFP) to mitigate the Chinese retaliatory tariffs. Using the universe o

Abstract This paper develops a model to study how suppliers' financial constraint interact with suppliers' position in a global value chain. I embed financial frictions into the property‐rights model of the global value chain, as in Antràs and Chor ( Econometrica , 2013, 81 , 2127), to derive the optimal allocation of ownership rights along the global value chain. The model predicts that multinational firms are more likely to integrate downstream intermediate input suppliers in countries with we

Abstract Do multinational enterprises (MNEs) transfer gender‐equal employment practices across borders? Using firm‐level data for Korea, a country with low gender equality, we find evidence that MNEs bring their home countries' gender norms in employment with them. Foreign‐acquired firms report 2–12 percentage‐points higher female shares of permanent main‐task workers at firm headquarters compared with nonacquired firms and the differential increases with the level of gender equality in the MNEs

We develop a command, weaktsiv, for two-sample instrumentalvariables regression models with one endogenous regressor and potentially weak instruments. weaktsiv includes the classic two-sample two-stage least-squares estimator whose inference is valid only under the assumption of strong instruments. It also includes statistical tests and confidence sets with correct size and coverage probabilities even when the instruments are weak.

This paper shows that the ancestry composition shaped by century-long immigration to the US can explain the current structure of global supply chain networks.Using an instrumental variable strategy, combined with a novel dataset that links firm-to-firm global supply chain information with a US establishment database and historical migration data, we find that the co-ethnic networks formed by immigration have a positive causal impact on global supply chain relationships between foreign countries

Abstract Conventional international trade theory predicts that bilateral offshoring flows will be highest when two countries have very different relative factor endowments. In contrast, the new trade theory contends that offshoring is more likely to exist when countries’ relative factor endowments are similar. This paper empirically tests the relationship between offshoring and relative factor endowments, measured by the skill overlap index between two countries and finds evidence that there is