There's one part of your message I neglected to reply to, Allin:
<snip>
> There ought to be a non-arbitrary relationship between the
> cost of training and the "ability to create additional value
> it imparts"... <snip>
Let's apply the use-value/exchange-value analysis to this. The
exchange-value of the "commodity" training will, like all other
commodities, be the exchange-value of the commodities used up in its
production. The use-value of this commodity is its ability to increase
the value-productivity of the input "commodity" unskilled labor, by
transforming it into a new "commodity", skilled labor. This use-value
can be expressed in quantitative terms as an increase in the productive
ability of skilled labor over unskilled.
The purchaser of this commodity skilled labor thus pockets surplus-value
as a result of the exchange--precisely as with the purchase of unskilled
labor, with which Marx's analysis begins.
Who is the purchaser likely to be? In the early days of capitalism, a
capitalist. But perhaps the pressure exerted by the labor movement to
gain access to education was in part motivated by the desire to let some
workers get their hands on part of this surplus. Thus when we look at
modern-day education of skilled labor, when subsidised by the State and
partly paid for by the workers themselves, you can argue that the higher
wage they get includes part of the increase in value-creating ability.
The reason for putting the word commodity in inverted commas above is
because, on several grounds, each thing mentioned is not a strict
commodity: all three have the ability to create value. This accounts for
some of the complexities you mention. Training itself will be a peculiar
industry, the wage for trained workers will reflect in part their
use-value, and so on.
Cheers,
Steve