Doug Kanter wrote:
....
Now that we've eliminated evil as a motive, what's left? As a person who
understands business, what OTHER reasons can you come up with? There HAVE to
be reasons. What are they?

Again, no one else has said it was "evil" although I do believe it
verges on unethical (although I'm sure those who choose to do so can
convince themselves that it's ok because, after all, the label says what
is in the container).

Actually, the reasons are quite simple--

1. People are price-conscious...see the "99 cent" pricing syndrome.

2. People have been conditioned to expect certain things to be in
certain size packages--coffee in 1-lb tins, for example. People tend to
not actively scan similar-sized containers for the actual label, so it
is possible to "get by with" a price increase, on the whole, w/o
actually acknowledging it. This is, of course, the previous argument
against the practice, but it is a real factor in the pricing and
purchasing mentality.

So it boils down to an argument in psychology and the marketeers and
advertisers have determined they optimize their overall return by using
the subterfuge of raising prices by lowering quantity as opposed to
raising prices on fixed quantities.