Did the German aviation tax have a lasting effect on passenger numbers?

The taxation of aviation is a frequently discussed component of governments’ efforts to mitigate greenhouse gas emissions. This study examines the impact of the German aviation tax on passenger numbers during the period 2011-2019 using five panel data estimators and a Specification Curve Analysis (SCA) to assess the robustness of the results to changes in the specifications of the econometric model. Employing five base models, we find that the tax induced a 6-11% reduction in the number of passengers departing annually from Germany in the first two years after implementation. For later years, estimated effects are more ambiguous. The SCA, comprising 175 alternative specifications, corroborates our main findings while showing a slightly wider range of effect sizes, especially on the upper bound. The results show that the choice of econometric method can affect research outcomes, especially for the fourth year of the tax and onward.