World income grows fast without verifiable climate-change impacts on the economy. The growth spell can end if climate impacts turn real but this can take decades to learn. We develop a tractable stochastic climate-economy model with a hidden-state impact process to evaluate the contributions of...

It is tricky to design local regulations on global externalities, especially so if firms are mobile. We show that when costs and outside options are firms' private information, the threat of firm relocation leads to local regulations that are stricter, not looser. This result is general and...