  Berkovitz (2002, section 5) argues that Maudlin's argument is, in effect, that if such retro-causal theories were true, they would involve closed causal loops in which the probabilities of outcomes that these theories assign will certainly deviate from the statistics of these outcomes. And, similarly to Arntzenius's argument, Maudlin's argument also rests on untenable assumptions about the nature of probabilities in causal loops (for a further discussion of Maudlin's and Berkovitz's arguments and, more generally, the prospects of Cramer's theory, see Kastner 2004). Furthermore, Berkovitz (2002, sections 2 and 5.4) argues that, similarly to relativistic parameter-dependent theories, the main challenge for theories that postulate retro-causality is not causal paradoxes, but rather the fact that their predictive power may be undermined. That is, the probabilities assigned by such theories may fail to predict the frequency of events in the loops they predicate. In particular, the local retro-causal theories that Maudlin considers fail to assign any definite predictions for the frequency of measurement outcomes in certain experiments. Yet, some other theories that predicate the existence of causal loops, such as Sutherland's (2006) local time-symmetric Bohmian interpretation of quantum mechanics, seem not to suffer from this problem.