Using administrative data on the universe of UK taxpayers we study the responsiveness of top earners to tax rates. We leverage two large tax reforms affecting top earners – one in the UK and one in France – to determine the scale of both emigration and immigration responses. Our setting allows us to examine heterogeneity in response by income level and by ex ante probability of migration, for both natives and migrants. We develop a model that rationalises these results, and structurally estimate model parameters to infer the long run stock and migration elasticities.

(coauthored with Cesar Poux, LSE III and Andy Summers, LSE Law)