The responsiveness of high-income earners to taxation is a central aspect of tax system design. This column presents patterns in the tax elasticity of top earners for up to 30 countries over a period of 115 years. Tax elasticities vary tremendously over time, space, and income, with a J-shaped pattern emerging over the past century. Tax avoidance behaviour strongly influences the elasticity of the very top earners, while there is less support for the role of labour supply responses across earners.