Bern has been rated the most liveable city in Europe again, according to one expert ranking. Clean air and safe streets have put Switzerland’s unofficial capital in the top spot for the third year running. Analysts at mobility consultancy ECA International evaluated more than 500 locations around the world to see where expatriates feel most at home. “With top facilities, minimal air pollution and low crime rates, Bern is a very attractive city for expatriates and their families,” says senior location ratings analyst Neil Ashman. “Swiss, Dutch and Scandinavian cities fill out the top 10 most li…