The policy shock of all regions simultaneously achieving the co-benefit of the climate policy is not analyzed. The reason is that this paper analyzes the first-order impacts at the macro- level of sectors confronted with air pollution policies in an international context. It refrains from the possibility that other regions simultaneously impose an air policy, which changes the trade pattern as well. These changes will produce other (and often higher) costs for the different regions than in the four separate air policy scenarios. The (avoided) costs involved with these air policy scenarios should indicate the economic value of the co-benefits of the related climate policy scenario only. Therefore they should contain only the first-order region- specific responses from changing trade patterns from air policies.