In this study, researchers looked at how people in Japan feel about carbon taxes, a way to fight global warming. They found that when other countries have strong carbon pricing, more people in Japan support it too. But if other countries have weak carbon pricing, support in Japan decreases. Knowing that other countries have lower carbon prices can make support in Japan drop even more than if other countries had no carbon taxes. This shows that what other countries do affects how much people in Japan support carbon taxes. However, the study also found that certain ways of designing carbon taxes in Japan can make up for the negative effects of other countries not cooperating on this issue.