^^ I presume they used the manufacturer recommended maintenance and typical dealer costs. When I owned Prius vehicles I maintained them very well outside the dealership and ended up paying about 0.5 cents a mile; that is, WAY less than the costs presumed in this study. So both cars can be cheap to maintain or expensive, but it makes sense to use the same rules for comparison.
So I don't fault the study for that reason, and I mostly agree with their somewhat softly said conclusion: EVs are cost competitive when paired with inexpensive PV. That said, 95% of the cars sold in the US today are not "cost competitive" with the Toyota Corolla or Prius so clearly no one would buy any of those cars without subsidy.
Oh, wait. Never mind.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Car is now enjoying an easy life in Colorado
3/2018: 58 Ahr, 28k miles
2018 Tesla Model 3 LR, Delivered 6/2018