<< In 1996, economist Robin Hanson coined the term “The Great Filter.” Hanson, a professor at George Mason, and an adherent of “prediction markets,” put together several themes related to Fermi and Drake when putting together his approach. Paraphrasing his original thesis, we can see that there are good reasons to expect a large number of alien civilizations based on the number of stars and planets. But clearly there are not a large number of alien civilizations. In fact all the evidence we have suggests that there are exactly none. >>
https://www.dailykos.com/stories/1809560