[ChrisV]

I think the confusion is arising because people are using EV in different senses. A lot of people only use EV in the context of change in EV as the result of a play.

No play in a SNG has an EV of zero. Every play has an EV measured in percentage of the prize pool. The question is therefore what you use as your baseline for measuring change in EV (equity).

Those saying that folding has a non-zero change in EV are using the equity before the hand started as the reference point. Others prefer to use the EV of folding as the reference point, in which case the change in EV of folding is 0 by definition.

Usually when people say "+EV" they mean compared to the other candidate play in that specific situation. I think this argument is all meaningless semantics and a thread hijack, which should end here.