This is just completely, ludicrously, wrong. Marx never speaks of "socially necessary *abstract* labor time"--he always speaks of "socially necessary labor time." And the unit of measure is very explicitly "average"--"*durschnittsgrad*"--labor time. It is never *unskilled*--*unerkundig* or *ungelernt*--labor time.
Shane Mage
"When we read on a printed page the doctrine of Pythagoras that all things are made of numbers, it seems mystical, mystifying, even downright silly.
When we read on a computer screen the doctrine of Pythagoras that all things are made of numbers, it seems self-evidently true." (N. Weiner)