Are 72% of prison inmates in Switzerland foreign?

The podcast episode addresses a listener's query regarding Donald Trump's claims about the high percentage of foreign nationals in European prisons, specifically in Germany, Austria, Greece, and Switzerland. Tim Harford interviews Professor Marcelo Aebi, a criminologist and lead author of the Council of Europe report cited by Trump. Professor Aebi confirms the accuracy of the numbers (e.g., 72% in Switzerland) but explains that Trump cherry-picked the highest figures. He clarifies that the high percentages in Switzerland are due to its geographical location as a crossroads in Europe, a significant number of cross-border workers, a multicultural society with a large foreign-born population, and policies on pre-trial detention for those without a legal address. Aebi also distinguishes between legally resident foreigners and those without legal status, noting that the latter group, including "crime tourists," disproportionately contributes to the prison population, particularly in remand. He emphasizes that Switzerland has a low overall prison population and short sentences, and that the issue is complex, without easy solutions due to the country's reliance on open borders for its economy. The situation in Greece is attributed to its position on the front line of illegal immigration and human trafficking.