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[greenyes] Benefits of Glass Recycling
Gosh, folks, I apologize for the consternation that I appear to have spawned
with my original posting.  I tried to answer a question, but there are a lot
of questions to which my answer doesn't apply.  I also apologize for how
much space this has taken up on GreenYes and promise that this will be my
last post on the subject.  I wouldn't have responded this time, but felt
like what I had said in the two previous posts was being seriously

The question I was trying to answer was what are the benefits of recycling a
bottle, a shard or a ton of cullet versus not recycling any glass at all.
As everyone seems to agree there are the first round energy and
environmental benefits from substituting that bottle/shard/ton for virgin
materials in making new glass containers.  What I was trying to point out is
that there are also a time series of additional benefits that accrue from
the many, many additional rounds of recycling spawned by that initial round
of recycling, versus the loss of all those benefits in the throw all glass
away all the time community.  And I was using the typical economics approach
of marginal analysis to find a way to quantify those additional benefits.

The concept is to imagine recycling that bottle/shard/ton, and to think
about the flow out through time that is lost when you don't recycle any
glass at all.  The total benefit of recycling that additional
bottle/shard/ton is calculated by the little formula that tells you how to
total up the amount of recycling that comes from the infinite sequence of
ever smaller amounts of recycling that would be lost if you didn't recycle
that bottle/shard/ton, lost all the recycling spawned by that
bottle/shard/ton, and didn't recycle any other bottles/shards/tons either.
This total is the marginal amount of recycling versus the system that
doesn't do any recycling of glass.

I suppose to make it visually concrete, one could imagine that all glass is
thrown away except one batch of bottles that are tinted a special color so
as to visually track their fate.  These bottles are recycled at an 80% rate
into new specially tinted bottles.  The other 20% and all non-specially
tinted bottles are thrown away.  Then for whatever number of special tinted
bottles you had initially, you could make 80% as many after the first batch,
80% of 80% on the third go round, etc.  The solution to the question of how
many recycled bottles will you ultimately make and what will be the energy
and environmental benefits of those bottles is a total that is 5 times
bigger than the number of bottles and benefits from the first round of

When confronting the question of what are the benefits of recycling glass
versus throwing all glass  away all the time, I think this is a very
reasonable way to quantify energy and environmental benefits from recycling.
The important reason for focusing on effects and benefits at the margin is
that they have a very intimate relationship to value and price and cost, and
on this basis help us conceptualize what recycling is worth.  Also, this
analysis is definitely pointed toward a discussion like that reported as
having taken place on This American Life, and is not intended to serve as
some sort of general case applicable to answering all the many, many other
important questions involved in glass recycling.  Finally, this analysis
provides a way to compare the benefits over time of recycling versus not
recycling -- it quantifies the dynamic life cycle sequence of avoided virgin
materials use that accrues to a recycling society versus a throw away
society without involving any quantitatively intractable infinite sums of
annual energy and environmental benefits.

Jeffrey Morris, Ph.D.
Sound Resource Management - Durham
3206A Myra Street
Durham, NC 27707

WA: 360-319-2391
NC: 919-403-1406

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