A Cautionary Data Tale

Colleague Wim Vandevelde from Brussels passes along this note and link,  make sure you have your models straight: " ... How biased selection and pre-processing of data, and an  (unintentional ?) Excel reference error  yielded a much  contested macro-economic ‘insight’ into  the relationship between country debt ratios and economic growth –  and how that correlation (if there was one to start with)  was mistaken for causation... "