Robert K. Merton listed five possible causes of unanticipated consequences in 1936:[13]
Ignorance, making it impossible to anticipate everything, thereby leading to incomplete analysis
Errors in analysis of the problem or following habits that worked in the past but may not apply to the current situation
Immediate interests overriding long-term interests
Basic values which may require or prohibit certain actions even if the long-term result might be unfavorable (these long-term consequences may eventually cause changes in basic values)
Self-defeating prophecy, or, the fear of some consequence which drives people to find solutions before the problem occurs, thus the non-occurrence of the problem is not anticipated