 Homework #10 due Dec. 2 nd  Exam #4 on Dec. 2 nd  Next week – Group Presentations Group Papers – Dec. 9 th Tuesday – Groups 1,2,3 Thursday – Groups 4,5,6 FINAL EXAM – Thursday Dec. 16  Section am  Section 2 - 3:10pm

 8% of the earth’s weight ( × tonnes)  100% recoverable  52% of aluminum cans are recycled  In 1999, the U.S. produces about 8 billion pounds of primary aluminum per year.  The U.S. produces an additional 8 billion pounds of aluminum coming from recycling per year.

 A = represents the stock of a resource  a = represents the recovery rate  Amount used over 4 years is A+ A*a + A*a 2 +A*a 3 A/(1-a) for infinity

 Collection Costs  Transportation Costs

 Aluminum is very reactive with oxygen, so salt  is added.  When aluminum cans/products are remelted for recycling, a byproduct, called dross or salt cake, is created.  Depending on the smelting process used, this by-product has amounted to about 1 million tons per year and is primarily disposed in landfills.  Salt cake is a concern because of the energy and material wastes as well as the disposal problems it presents.

 The Disposal Decision Recyclable waste comes from either new scrap or old scrap. New scrap is residual material from a production process while old scrap is recovered from used products. When the private marginal cost of disposal is lower than the marginal social cost, the market level of recycling is inefficient.

Copyright © 2009 Pearson Addison- Wesley. All rights reserved Disposal Costs and Scrap Market  If consumers bear the true marginal disposal cost, more materials could be integrated into production process; price falls, and total consumption of inputs would increase as well as the use of recycled materials. Correct inclusion of disposal cost would increase the amount of recycling and extend the economic life for depletable and recyclable resources.

 U.S. has achieved higher recycling rates 32.5% 52% of paper 31% of plastic and soft drink bottles 45% of aluminum cans 63% of steel packaging 67% of large appliances  Transport, labor and processing costs are usually significant and play a large role in overall recycling rates.  As recycling becomes more cost competitive, however, manufacturers rely more heavily on recycled inputs as well as product design.

Copyright © 2009 Pearson Addison- Wesley. All rights reserved  Subsidies on raw materials are another source of inefficiencies.  One example is the Mining Law of Raw materials are artificially cheap. Undermine the market for recycled inputs.

 Noninternalized environmental damages from the use of virgin materials will also bias the market away from recycled materials. These might be damages from extraction or from processing.  Host fees are being used to address the issue of siting of landfills. Host fees compensate the community that agrees to house the landfill.

 Public polices include volume pricing, refundable deposits and taxes. Volume pricing are disposal charges that reflect the true social cost of disposal. A refundable deposit system is typically designed to be an initial charge that reflects the cost of disposal and to provide a refund that encourages recycling and helps conserve virgin materials. Taxing virgin materials and subsidizing recycling activities can also promote recycling.

 Homework #10 due Dec. 2 nd  Exam #4 on Dec. 2 nd  Next week – Group Presentations Group Papers – Dec. 9 th Tuesday – Groups 1,2,3 Thursday – Groups 4,5,6