The popularity of most politicians follows a similar course. Some grow to be palatable enough to win an election and then fall increasingly out of favour before eventually being booted out. Their reputations then pick back up again the longer they have been retired before getting one final boost.

Angela Merkel has set out to secure her reputation in a 700-page memoir in which the former German chancellor defends her 16 years in office. Critics increasingly believe that her leadership led Germany to chronic underinvestment,