>>if 2 books exchange for 3 bread and 1 socks exchange for 3 jam, then 2
books and 1 socks would exchange for 3 bread and 3 jam. This is
unlikely
as bread and jam are complementary and therefore together would demand
more
books and socks in exchange than they would in the antecedent exchanges.
Is this exchange supposed to take place in some market-place, or merely
in the head of the thinker? The way you put it, it sounds more like a
consumer's preference map than a system of prices (of course, there are
schools of thought that try to build a link between these).
Actually, re-reading this, how do the bread and jam get together to
express their joint demand? Even under capitalism commodities need human
agents to represent them.
BTW, my local supermarket sometimes does joint promotions (e.g.
strawberries jointly with cream), but so far it hasn't offered to take
my books or socks in payment.
Steve also writes (apropos of exchange in an already monetised economy
where two dollars of oranges exchange for two dollars of steel):
>>But isn't this like wondering which weighs more, one hundred pounds of
feathers or one hundred pounds of steel?
As Alan has already pointed out, one can compare weights without a
concept of mass. But I'd suggest that the potential for science arises
precisely when one starts to ask questions like this -- because they
carry the implication that there is something *behind* weight that
*causes* the equality on non-equality of heavy objects.
Julian