Optimal Pollution Control in Agricultural Production: Biodegradable vs Plastic Mulches
——General Model and Application in the Plastic Mulches
Jingze Jiang1, Tom Marsh1, and Eric Belasco2
1 School of Economic Sciences, Washington State University2 Department of Agricultural and Applied Economics, Texas Tech University
Outline
• Introduction and Motivation
• Purpose and Objectives
• Model
• Simulation (Plastic Mulches )
• Preliminary results
• Future work
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Introduction and Motivation--Studying the Widely Used Plastic Mulches
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Strengths Weaknesses
1. Increase production:(weed control, moisture
conservation, temperature modification)
2. Affordability(1.5$/lb-solid black)
Plastic Mulches Emission:1. productivity decreased2. Cost of disposing 3. Environmental problems:(wildlife
and livestock; carbon dioxide in the atmosphere)
Opportunities Threats
Improvement in Disposal Methods:1. Recycling2. Compositing Reduce cost and environmental
damage
New Materials-Biodegradable Mulches:1. Save disposal fee and labor fee2. Save environmentSo far the price is around twice
higher ; The quality is questioned.
Purpose and Objectives
• 1) By considering the cost of dealing with plastic mulch waste, what is the best choice for growers when choosing between conventional and biodegradable mulches?
• 2) What is the best choice among different mulches and waste disposal methods to achieve a social optimum?
• 3) Is government regulation necessary?
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Model-Growers’ Choices
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Model-Setup
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Objective—Maximizing Profit:
Model-Setup
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Constraints:
MP: BP: DC:
Solution:
Simulation (Plastic Mulches )-Model Adjustment
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• Plastic Mulches in Real World:
- 1. The illegal fine is from 5,000$ to 26,000$; The highest landfill tipping fee in WA is
0.056$/lb charged by LRI Landfill in 2010; The recycling fee is around twice higher than
land-filling tipping fee.(http://www.ecy.wa.gov);
- 2. If the grower does not deal with the used mulches, he would lose at least 2500$/acre, which is 73 times higher than the landfill tipping fee
- The grower once choose to use plastic mulches, he should prepare to pay for the disposal fee.
Simulation (Plastic Mulches )-first question
• What is the minimum increased yield caused by using plastic mulches to certify that the grower will use plastic mulches ? (not choosing 1.1)
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Simulation (Plastic Mulches)-Data• We choose one acre of tomatoes field as measure unit.
• The tomatoes 1989-2009 seasonal prices($/lb) in west US are collected from USDA website.
• The tomatoes 1989-2009 seasonal yield data (lb/acre) in WA are regress onto the US 89-09 yield data from USDA website.
• We use 1989-2009 LLDPE film seasonal real price data to measure ($/lb)
• Landfill tipping fee Data in WA is collected from Department of Ecology State of Washington and NSWMA’S 2005Tipp Fee Survey
• Other data, namely mulches usage (lb/acre), installing and removing mulches labor cost($/acre), are from surveyed farms.
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Preliminary result
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Preliminary results
• If the plastic mulches cannot increase the yield by 8.66%, the grower should not choose to use the plastic mulches.
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Future work
• Simulate the social cost for using the plastic mulches
• Simulate the conditions under which the biodegradable mulches can generate more benefit for growers
• Compare the difference of the social cost between using the plastic mulches and biodegradable mulches.
• Discuss the necessity of the government intervention balancing the individual interest and social optimum
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