English

Probabilities of conditionals and previsions of iterated conditionals

Probability 2020-03-17 v2 Logic

Abstract

We analyze selected iterated conditionals in the framework of conditional random quantities. We point out that it is instructive to examine Lewis's triviality result, which shows the conditions a conditional must satisfy for its probability to be the conditional probability. In our approach, however, we avoid triviality because the import-export principle is invalid. We then analyze an example of reasoning under partial knowledge where, given a conditional if AA then CC as information, the probability of AA should intuitively increase. We explain this intuition by making some implicit background information explicit. We consider several (generalized) iterated conditionals, which allow us to formalize different kinds of latent information. We verify that for these iterated conditionals the prevision is greater than or equal to the probability of AA. We also investigate the lower and upper bounds of the Affirmation of the Consequent inference. We conclude our study with some remarks on the supposed ''independence'' of two conditionals, and we interpret this property as uncorrelation between two random quantities.

Keywords

Cite

@article{arxiv.1912.05696,
  title  = {Probabilities of conditionals and previsions of iterated conditionals},
  author = {Giuseppe Sanfilippo and Angelo Gilio and David Over and Niki Pfeifer},
  journal= {arXiv preprint arXiv:1912.05696},
  year   = {2020}
}