Coincidental Correlation
(post hoc ergo propter hoc)


    The name in Latin means "after this therefore because of this". This describes the fallacy. An author commits the fallacy when it is assumed that because one thing follows another that the one thing was caused by the other.
  1. Immigration to Alberta from Ontario increased. Soon after, the welfare rolls increased. Therefore, the increased immigration caused the increased welfare rolls.
  2. I took EZ-No-Cold, and two days later, my cold disappeared.
    Show that the correlation is coincidental by showing that: (i) the effect would have occurred even if the cause did not occur, or (ii) that the effect was caused by something other than the suggested cause.
    (Cedarblom and Paulsen: 237, Copi and Cohen: 101)
06 October 1995