“…There have been a series of studies to investigate global gas markets' integration. See Kim and Kim (2019) for discussions in these studies. The consensus is that global natural gas markets are regionally isolated; it has three major trading regions, Europe (Norway, Russia, and Algeria are major suppliers), North America (pipeline resource exporting within the U.S., Canada, and Mexico), and East Asia (Korea and Japan, and China since 2017, the major suppliers are the Middle East, Indonesia, Malaysia, and Australia) (Bachmeier & Griffin, 2006; Kim et al, 2020; Li et al, 2014).…”