That's interesting, but (at least from a quick look and a few text searches) they don't seem to explain what their "sanction contribution score" is. How are they sure that the cases where they "worked" are not regression to the mean (some authoritarian regimes just fall from time to time)? And how are they sure that there is not an equal number of cases where they do the opposite of what they intend? (maybe the Castrist regime would have fallen already if the country had been allowed to develop without sanctions).