About

My research interests lie in international macroeconomics and macro-finance, with a focus on capital flows, exchange rates, and financial stability in emerging market economies. My work examines how domestic investors’ international portfolios shape economies’ responses to global financial shocks and influence the effectiveness of exchange-rate and foreign-exchange intervention policies.

My previous research includes studies of fiscal policy effectiveness across different states of the macroeconomy and a study of cryptocurrency.

Research

Job Market Paper

Private vs. Official Absorption of Global Financial Cycle in Emerging Markets [Draft PDF]

Summary. This paper studies why domestic private investors absorb global financial shocks more strongly in some emerging market economies than in others. It develops a demand-system model in which residents’ sensitivity to expected excess currency returns determines both the transmission of foreign demand shocks and the need for foreign-exchange intervention. Using cross-country and security-level evidence, I show that private absorption is stronger when domestic investors hold more flexible international portfolios, reducing the need for official FX intervention.

Publications

  1. Shin, Junhyeok, and Sangyup Choi. "Household Indebtedness and the Macroeconomic Effects of Tax Changes." Journal of Economic Behavior and Organization, May 2023. [Paper]

    Summary. This paper studies whether household indebtedness changes the macroeconomic effects of U.S. tax changes. Using state-dependent local projections and exogenous tax shocks, it finds that tax cuts stimulate output much more when household debt is high, mainly through stronger consumption and labor-supply responses. The bottom line is that household balance sheets are an important determinant of fiscal-policy effectiveness.

  2. Choi, Sangyup, Seung Yong Yoo, and Junhyeok Shin. "Are Government Spending Shocks Inflationary at the Zero Lower Bound? New Evidence from Daily Data." Journal of Economic Dynamics and Control, June 2022. [Paper]

    Summary. This paper uses newly constructed daily data on U.S. government spending and prices to estimate how spending shocks affect inflation at the zero lower bound. It finds that prices fall, rather than rise, after a positive spending shock at the ZLB, and that the shock is more deflationary than in normal times. The results suggest that tighter credit constraints can weaken the inflation channel behind large fiscal multipliers.

  3. Choi, Sangyup, and Junhyeok Shin. "Bitcoin: An Inflation Hedge but Not a Safe Haven." Finance Research Letters, August 2021. [Paper]

    Summary. This paper uses a vector autoregression to study how Bitcoin and gold respond to inflation and uncertainty shocks. Bitcoin prices rise in response to inflation shocks but fall when financial uncertainty increases, unlike gold. The bottom line is that Bitcoin can hedge inflation but does not provide the same safe-haven protection as gold.

Teaching

TA

  • Topics in International Macroeconomics and Finance Johns Hopkins University, Spring 2026 and Fall 2024
  • Financial Markets and Institutions Johns Hopkins University, Fall 2025
  • Corporate Finance Johns Hopkins University, Spring 2025
  • Macroeconomics Yonsei University, undergraduate course in English, Fall 2020
  • Analysis of International Financial Market Yonsei University, undergraduate course in English, Fall 2019