Firm characteristics in empirical models for margins of international trade usually enter these models in linear form. If non-linearities do matter and are ignored this leads to biased results. Researchers, however, can never be sure that all possible non-linear relationships are taken care of....

This study examines how the impact of Tradable Green Certificates (TGC) on profitability and investment behavior varies depending on the vertical integration status of regulated firms. Our theoretical model predicts that vertical integration does not lead to higher profits when internal pricing...