• The Korean Journal of Applied Statistics
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• v.37 no.4
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• pp.509-523
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• 2024

This study estimates connectedness index among the US, China, Europe, Japan, and South Korea using monthly economic policy uncertainty (EPU) data from January 2000 to December 2023. The connectedness index allows us to analyze the effect of global economic uncertainty on domestic economic uncertainty. The EPU is used as a proxy for economic uncertainty. Inter-country connectedness index is computed from variance decomposition. The findings from forecast error variance decomposition show that three-fourths of total uncertainty comes from economic uncertainty in the own country and one-fourth of total uncertainty comes from economic uncertainty in the others. The analysis on net pairwise connectedness reveals that, even though the extent of the effect of economic uncertainty in one country from economic uncertainty in another country varies over time, economic uncertainty in South Korea, a small-open economy, is mainly affected by economic uncertainty in the others. The reverse situation rarely happens except in the specific occurrence such as the collapse of the credit bubble in 2003 and the subsequent years, the inter-Korean summit and North Korea-the US summit in 2018, and the period from the first outbreak of COVID-19 on the implementation of the government's severe regulation against COVID-19.

• The Korean Journal of Applied Statistics
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• v.33 no.5
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• pp.639-653
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• 2020

Baker et al. (Quarterly Journal of Economics, 134, 1593-1636, 2016) developed an Economic Policy Uncertainty (EPU) index for South Korea in the same way as the U.S. EPU Index. However, the South Korean EPU index of Baker et al. (2016) has limitations as it did not fully reflect South Korean situation in terms of keyword selection and the selection of newspapers. We develop monthly South Korean economic policy uncertainty indexes with different keywords and news media. Various analyses have been conducted in order to examine the usefulness of the newly compiled indexes.

• Asia-Pacific Journal of Business
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• v.14 no.4
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• pp.319-330
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• 2023

Purpose - The purpose of this paper is to examine the connectedness between categorical economic policy uncertainty (monetary, fiscal, trade and foreign exchange policy uncertainty) indexes and option-implied volatility index in Korea, Japan and the US. Design/methodology/approach - This paper employs the Diebold-Ylmaz (2012) model based on a VAR and generalized forecast error variance decomposition. This paper also conducts regression analyses to investigate whether the volatility indexes are explained by categorical policy uncertainty indexes. Findings - First, we find the total connectedness is stronger in Korea and Japan relative to the US. Second, monetary, fiscal, and foreign exchange policy uncertainty indexes are connected to each other but trade policy uncertainty index is not. Third, the volatility index in Japan and the US is mainly associated with monetary policy uncertainty while the volatility index in Korea is explained by fiscal policy uncertainty index. Research implications or Originality - To our knowledge, this is the first study to investigate the connectedness among categorical policy uncertainty indexes and the volatility index in Korea, Japan, and the US. The empirical results on the connectedness suggest that transparent policy and communication with the market in one type of policy would reduce the uncertainty in other policies.

• Environmental and Resource Economics Review
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• v.14 no.4
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• pp.817-838
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• 2005

In this paper, the resource adequacy as well as the optimum fuel mix is obtained by the following procedures. First, the regulation body, the government agency, determine the reliability index as well as the optimum portfolio of the fuel mix during the planning horizon. Here, the resources with the characteristics of public goods such as demand-side management, renewable resources are assigned in advance. Also, the optimum portfolio is determined by reflecting the economics, environmental characteristics, public acceptance, regional supply and demand, etc. Second, the government announces the required amount of each fuel-type new resources during the planning horizon and the market participants bid to the government based on their own estimated fixed cost. Here, the government announces the winners of the each auction by plant type and the guaranteed fixed cost is determined by the marginal auction price by plant type. Third, the energy market is run and the surplus of each plant except their cost (guaranteed fixed cost and operating cost) is withdrew by the regulatory body. Here, to induce the generators to reduce their operating cost some incentives for each generator is given based on their performance. The performance is determined by the mechanism of the performance-based regulation (PBR). Here the free-riding performance should be subtracted to guarantee the transparent competition. Although the suggested mechanism looks like very regulated one, it provides two mechanism of the competition. That is, one is in the resource construction auction and the other is in the energy spot market. Also the advantages of the proposed method are it guarantee the proper resource adequacy as well as the desired fuel mix. However, this mechanism should be sustained during the transient period of the deregulation only. Therefore, generation resource planning procedure and market mechanisms are suggested to minimize possible stranded costs.

• Journal of Korea Port Economic Association
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• v.39 no.4
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• pp.205-222
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• 2023

This study examines the impact of the changes to the port logistics before and after the COVID-19 pandemic. Specifically, the study focuses on analyzing the changes to Korea's container ports network. Furthermore, this study examines the influence of the ports in the container port network before and after the COVID-19 Pandemic using the network analysis method such as centrality indexes (degree centrality, closeness centrality, and betweenness centrality) to identify changes in the structure and properties of the networks between 2018 and 2021. In this study, We analyzes the changes in the container port networks of Busan, Gwangyang, Incheon, Ulsan, and Pyeongtaek-Dangjin, the five largest ports in Korea. As a result, in case of the Busan port, Singapore port plays an important role, while Busan port plays key roles in ports of Gwangyang, Incheon, and Ulsan. In case of the Gwangyang port, Port Kelang in Malaysia has become increasingly influential as a result of the Malaysian government's policies to overcome the pandemic. In the Incheon port, Japanese ports are playing intermediary roles between their ports and those in the Incheon port network. In the case of Ulsan port, the influence of Korean ports is high, and in the case of Pyeongtaek-Dangjin port, Southeast Asian ports play a role as intermediaries between ports. By analyzing the changes in Korea's port logistics networks, this study can be used as a reference point when responding to uncertainty situations that cause changes to port logistics, such as the COVID-19 pandemic, in the future.