Reading "Manuel de prospective stratégique, tome 1 : Une indiscipline intellectuelle" (Michel Godet), there was an interesting chapter about the most frequent error when doing foresight. General causes are: 1) Forgetting change (over-estimation) and inertia (under-estimation). 2) "Announcement effect": some predictions only aim at influence the evolution of the phenomenon and then contribute to its realization 3) Too much information (noise), few strategic information 4) Inaccuracy of data and instability of models (one should always ask whether a small modification in input data will change the output) 5) Error of intrepretation 6) Epistemological obstacles (looking at the tip of the iceberg / or where the light is)

Specific causes: 1) Uncomplete vision (leave behind other variables, disruptions, new trends...) 2) Excluding qualitative variables (that cannot be quantified 3) Thinking variables have static relationships 4) Explaining everything by looking at the past 5) Single future 6) Excessive use of mathematical models (mathematical charlatanry) 7) Conformism to gurus