A statistic correlation between two variables in an important tool to know whether there is a real dependency between them, however a thoroughly investigation is needed to understand if this dependency really exists.
Correlation of variables related to events does not mean that there is a relationship of cause to effect and, in case the relation exists, does not tell anything about which is the cause. This is especially true in case the events are concurrent in time.
Let’s bring forward as couple of examples:
- according to Max Weber, the economic development is a consequence of Protestantism but, other scholars that have made a deeper investigation into the economics in Middle Age now believe that the Protestantism has been a consequence of economic development
- apparently there is a correlation between population of storks and number of births.
If you want some fun with spurious correlation, look at website http://tylervigen.com/spurious-correlations
Gianluca di Castri (IdeaConsult) 