Skin effect is just gee whiz info at 60hz unless you are in the megawatt arena. It sure has nothing to do with any wire you can pick up a roll of.
I am confused by this statement. I learned that current flows on the outside of wire w/ alternating current (skimming affect) Whether it be solid or sttranded the current will flow on the outside of the wire.
A person asked about spliting the stranded wires and we got a crazy response regarding ampacities and " of wire. Answer should of been put all wire in same lug! When I see electricians who split stranded wire because it doesnt fit, I would like to smack them.
Remember in the code it also states "good workmanship" This is all to often ignored.