Equal Opportunities in Newcomb’s Problem and Elsewhere

Abstract

Abstract The paper discusses Ian Wells’s recent argument (Wells 2019) that there is a decision problem in which followers of Evidential Decision Theory end up poorer than followers of Causal Decision Theory despite having the same opportunities for money. It defends Evidential Decision Theory against Wells’s argument, on the following grounds. (i) Wells's has not presented a decision problem in which his main claim is true. (ii) Four possible decision problems can be generated from his central example, in each of which followers of Evidential Decision Theory do at least as well as followers of Causal Decision Theory (but the former typically have better opportunities for money). (iii) There is another case in which followers of Causal Decision Theory have the same opportunities for making money but end up worse than followers of Evidential Decision Theory.