I test H1 using both levels and difference-in-differences designs. The levels design examines whether firms that use derivatives on an ongoing basis indeed avoid more tax, on average, than firms that do not use derivatives. The difference-in differences design examines the tax effects of derivatives initiation and provides a focused setting in which to estimate the economic significance of derivatives-based tax avoidance. Corroborating evidence across both designs will allow for stronger inferences about the link between derivatives and corporate tax avoidance.