 One distinctive feature of the neutrino example is that it is ‘additive.’ It involves postulating the existence of a collection of qualitatively identical objects which collectively explain the observed phenomenon. The explanation is additive in the sense that the overall phenomenon is explained by summing the individual positive contributions of each  object.[21]  Whether the above approach can be extended to non-additive cases involving quantitative parsimony is an interesting question. Jansson and Tallant (2017) argue that it can, and they offer a probabilistic analysis that aims to bring together a variety of different cases where quantitative parsimony plays a role in hypothesis selection. Consider a case in which the aberrations of a planet’s orbit can be explained by postulating a single unobserved planet, or it can be explained by postulating two or more unobserved planets. In order for the latter situation to be actual, the multiple planets must orbit in certain restricted ways so as to match the effects of a single planet. Prima facie this is unlikely, and this counts against the less quantitatively parsimonious hypothesis.