This is classic comparing apples to oranges situation. It's not that straight-forward. You really need to define what you're measuring first or you're chasing shadows. If you're talking about SERP ranks then you already know there are loads of factors to consider, if you're thinking "the value of a link according to the search algo(s)" then you still have to consider Domain authority, Page authority, Domain Rank, Page Rank just as a basic plus quite a few other considerations, so it really isn't that simple.
I'm going to guess that you'll be disappointed to hear that, and just want a really straight and simple figure to work with, but I hate to continue the disappointment but comparing PR isn't the answer.
However - if you're asking a different question which is "how good are .edu & .gov links for ranking?" they are chuffing-well excellent !