{'fraction_non_alphanumeric': 0.030403537866224434, 'fraction_numerical': 0.003316749585406302, 'mean_word_length': 4.973597359735973, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The Doomsday Argument and the Self–Indication Assumption: Reply to Olum

In a recent paper in this journal, Ken Olum attempts to refute the doomsday argument by appealing to the self-indication assumption (SIA) that your very existence gives you reason to think that there are many observers. Unlike earlier users of this strategy, Olum tries to counter objections that have been made against (SIA). We argue that his defence of (SIA) is unsuccessful. This does not, however, mean that one has to accept the doomsday argument (or the other counter-intuitive results that flow from related thought-experiments). A developed theory of observation selection efects shows why the doomsday argument is inconclusive, and how one can consistently reect both it and (SIA). I. THE RELATION BETWEEN THE DOOMSDAY ARGUMENT AND (SIA) The doomsday argument purports to show that we have systematically underestimated the probability that humankind will become extinct relatively soon. Originated by Brandon Carter and developed at length by John Leslie,' the doomsday argument argues that we have neglected to take fully into account the indexical information residing in the fact about when in the history of the human species we exist. In a nutshell, your birth rank (i.e., your position in the sequence of all humans) is roughly 70o billion. That you should have such a low birth rank is less surprising, and more probable, if the total number of humans that will ever have existed is, say, 2oo billion rather than, say, 200 trillion. (By 'probability' we here mean rational subjective credence.) Given these unequal conditional probabilities, one can derive from Bayes' theorem that the probability of impending doom goes up after conditionalizing on your birth rank. That is, after realizing the full evidential import