The purpose of this research was to examine the performance of agrivoltaic systems, which produce crops and electricity simultaneously, by installing stilt-mounted photovoltaic (PV) panels on farmland. As PV power stations enjoy remarkable growth, land occupation with the purpose of establishing solar farms will intensify the competition for land resources between food and clean energy production. The results of this research showed, however, that the stilt-mounted agrivoltaic system can mitigate the trade-off between crop production and clean energy generation even when applied to corn, a typical shade-intolerant crop. The research was conducted at a 100-m2 experimental farm with three sub-configurations: no modules (control), low module density, and high module density. In each configuration, 9 stalks/m2 were planted 0.5 m apart. The biomass of corn stover grown in the low-density configuration was larger than that of the control configuration by 4.9%. Also, the corn yield per square meter of the low-density configuration was larger than that of the control by 5.6%. The results of this research should encourage more conventional farmers, clean energy producers, and policy makers to consider adopting stilt-mounted PV systems, particularly in areas where land resources are relatively scarce.

This paper is to explore the challenges the student mobility will face under the fourth industrial revolution from the perspective of education economics. The Fourth Industrial Revolution affects not only economic activities such as production, sales, and consumption, but it also has an impact on education. Few previous studies, however, have explored the influence on international student mobility in the higher education sector. How does the Fourth Industrial Revolution change the cost-utility structure of studying abroad? What challenges do higher education institutions face? This paper analyzes the impact of the Fourth Industrial Revolution by employing an economic theoretic model. Some of the socioeconomic changes caused by the Fourth Industrial Revolution, such as an increased global knowledge stock, increase demand for study abroad, while others including knowledge that rapidly becomes obsolete and the relatively high costs of studying abroad, reduce it. Higher education institutions not only face risks but also have opportunities in the era of the Fourth Industrial Revolution. The key to their success is in providing more opportunities to develop the non-cognitive skills necessary for jobs that machines cannot do.

This study investigated the scientific progress of climate security studies through a literature review and discussed its risks in East Asia. Climate security refers to the protection of countries and societies from conflicts and riots caused by climate change. As climate change becomes more apparent, climate security has been vigorously debated in the international community. Climate security risks in East Asia, however, are not yet widely discussed. This literature review identified that climate change increases the risk of conflict not only through direct threats to people and societies from extreme weather events and natural disasters, but also indirectly through various pathways, such as shortages of water and other resources, outbreaks of climate migration, disruptions in food production, economic and social disturbances, and geopolitical changes. Considering the climate-conflict pathways identified by the literature review, East Asia may face (1) tensions caused by climate emigrants, (2) conflicts over loss of territories and fishery areas, (3) conflicts caused by water shortage, (4) instability caused by heavy rain and floods, and (5) geopolitical risks of rare earth sourcing, green industrial policies, and the Arctic. East Asian countries need to lower climate security risks in the region through cooperative international measures such as climate change mitigation, vulnerability reduction, and policy dialogue.

This study re-examined the effect of official development assistance (ODA) of five major donor countries (France, Germany, Japan, the United Kingdom, and the United States) on foreign direct investment (FDI) using panel data from 2003 to 2020. In addition to the system Generalized Method of Moments (GMM) with the gravity model, the Granger causality test and impulse response analysis with the panel VAR model was conducted. It was concluded that ODA did not necessarily have an effect on FDI since the 2000s. It is also suggested that the vanguard effect of Japanese ODA, as indicated by some previous studies, appeared mainly in the 1990s and may not be sustainable. The novelty of this study is to verify the effects of the ODA of major donors on FDI using new data from the 2000s onward, especially to reveal that the vanguard effect of Japanese ODA has not been observed since the 2000s. A limitation of this study is to determine only the presence or absence of a general trend at a statistically significant level. Therefore, further research on individual cases is expected to find how ODA has affected the investment decisions of individual companies.

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