Sin ttulo de diapositiva

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ECONOMICS OF SPECIES EXTINCTION
Extinction is an economic problem precisely
because it is a resource allocation problem
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Clark Model (1973)

• Takes into account
• Extinction of individual well-recognised species
• Biodiversity loss
• Based on 3 factors
• Open access to resource
• Relative price to cost of harvesting the resource
• Relative growth rate of the resource

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Policies derived from Clarks Model

• Decrease the price of the resulting products
• Increase the costs of the production process
• Criminalisation of the production process
• Example African Elephant
• Little to be done affecting resource growth rates
  or habitat conditions

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Timothy Swansons Model

• Although these policies, the world was heading
  toward a period of severe mass extinctions
• Investment based model
• Species as a productive asset

Conclusion
Slow growth rates relative to other assets in the
economy is a route to species extinction.
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• Humans control basic necessities to survive
  food, water, light, air,...

EXTINCTION AS A HUMAN RESPONSIBILITY Bioeconomic
model Investment on resources for the survival
of the species or competing uses for the
resources????????????????????
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Logistic Growth Function

• H (x) x(R-x)
• H (x) flow from a stock
• X existing stock
• R available carrying capacity
• - Niche to be filled energy to fill it
• - Niche is filled energy to maintain it
• Growth rate is linked to the available niche

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Revise model of extinction

• Best alternative use of the resources implicide
  cost.
• If a species is using some resources, it must be
  able to afford a competitive return of them
• Marginal rate of return

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Revised model of extinction

• Three routes of extinction
• Stock disinvestment
• Management resources diversion
• Base resource conversion

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Stock disinvestment

• Resources with HIGH VALUE and LOW GROWTH
• Invest the funds in other assets????????
• Resource mining
• Deforestation of the tropical hardwood forests

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Management resources diversion

• Resources of MEDIUM VALUE and LOW GROWTH
• Not individual investment or commitment of public
  resources
• Species used for trading
• African elephant, rhinoceros, wild birds

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Base resource conversion

• LITTLE OR UNKNOWN individual VALUE to humans
• Better alternatives for resources
• Land is being deforested and changed into other
  forms of use.
• Unknown life forms such as plants and insects

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Conclusion

• Biological resources into economical resources
• Species which are worthy to survive
• Key of extinction HUMAN INVESTMENT

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THE UNDERLYING CAUSES OF BIODIVERSITY DECLINE
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• The causes of biodiversity decline are many and
  diffuse.
• Even in the absence of human pressures.
• There are several natural mechanisms that can
  result in biodiversity loss or species
  extinction. But our interest lies in human
  induced processes.

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• Each of the following processes can induce
  biodiversity decline
• Land conversion away from high diversity
  supporting uses
• Exploitation of wild species (overexploitation)
• Introduction of exotic species into new
  environments
• Homogenisation of agricultural practices
• Air, water and ground pollution
• Climate change.

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Extinction in the context of marine resources

• Overexploitation is the main cause fishing
  and hunting oceanic species at unsustainable
  levels.
• Open access resource was likely to be
  unsustainable if two conditions occur
• The prices/cost ratio of harvesting the resource
  was high.
• The natural growth rate of the resource was low.

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Extinction in the context of terrestrial
resources

• No reason to adopt an open access regime one
  nation has the responsibility of the territory.
• The regulation of natural resources is an
  investment decision
• It cannot be assumed that all existing resources
  are going to be protected.
• SELECT
• The choice on how to allocate the resources
  determines which species will proliferate an
  which will perish.

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• Three routes to extinction for terrestrial
  species
• Diversion of supporting capital high price/cost
  ratios but low growth rates.
• Divestment of capital low growth and net value
  low.
• Conversion of capital little or no known value.

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MODELLING SPECIES EXTINCTION THE CASE FOR
NON-CONSUMPTIVE VALUES

• (By Robert R. Alexander)

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• OBJECTIVE
• To come up with a bioeconomic model of species
  extinction

• STEPS
• 1º) The causes of why certain species dont tend
  toward extinction based in tha Clark Swanson
  theories
• 2º) The conceptual model based on non-consumptive
  values
• 3º) Implications for species extinction
• Example The African Elephant model

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1- THE CLARK MODEL

• Clark based his models of extinctiion on Gordons
  seminal fisheries model
• Extinction of species results from three factors
• having open access to the resource
• relationship between price and marginal cost of
  nesting the resource
• growth rate of the resource relative to the
  discount rate
• If price always overpaseses unit cost, and if the
  discount rate is large enough, then, maximizing
  rate is relative to the grotwh rate, so the
  larger the discount rate, the lower the growth
  rate

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1- THE CLARK MODEL

• Problems
• Sine ivory is the principal resource making the
  elephant valuables, eliminating the markets for
  ivory tends to remove one of the major incentives
  to protect these species
• The revenues used to protect the elephants are
  now not available this reduces its stock value
  and reduces its availabillity to compete against
  alternative usses of land

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2- THE SWANSON MODEL

• Swanson proposes ways to adpat this model to
  terrestrial species
• He includes resources coming from the erath taht
  are needed by the endangeres species survival.
• Terrestrial species have to generate growth to
  compete with other capital opportunities and to
  compete with the opportunity costs of resources
  they need for survival

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3- THE CONCEPTUAL MODELS

• Clark and Swanson models consider only the
  consumptive value
• But some of the values of many species are
  non-consumptive
• Tourism use value and non-use existence value.

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4- IMPLICATIONS FOR SPECIES EXTINCTION

• The Africant Elephant...
• The elephant growth rate has to be equal of
  return on capital at some positive level
• But it is hard to keep the equation equal
• We cannot change the growth rate of the elephant.
• Since the population growth in Africa is expected
  to double by 2050, this will increase the cost of
  the land for wich the elephant must compete,
  wich, turnos out to be the biggest threat to the
  survival of the elephant

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SUMARIZING....

• These models demonstrate tha we have to consider
  both, consumptive and non-consumptive values,
  when exploring the potencial that endangeres
  species have to compete succesfully for the
  resources they need to survive

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• PRESENT- VALUE MAXIMIZATION RESULTS IN
  EXTERMINATION OF THE RESOURCE?

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INTRODUCTION TO THE MODEL

• Bioeconomic model mathematical model for the
  commercial exploitation of a natutural animal
  population
• Assumptions
• Equilibrium population level, Rent- maximitation
  level, Maximum- yield level and the zero
  equilibrium population
• Notion of a reproduction curve
• Fix price
• Unit cost depens only on populaion size

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PROCESS THAT FOLLOWS THE EXPLOITATION

• 1. Stage of expanding harvest
• 2. Increase of the exploitation
• 3. Solutions are required
• Conservation mesures are taken quite rapid
• Action is taken too late

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CONCLUSION

• EXTINTION MAY RESULT FROM PRESENT VALUE
  MAXIMIZATION

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CONCLUSION

• The main conclusion of the analisys is that
  exploitation leads to economic inefficiency and
  sometimes to the over-exploitation. However, few
  studies consider explicity the possibility of
  complete extermination of population.
• THE MODEL IS NOT A WELFARE MODEL we can not
  afirm that the extintion is socially optimal.

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THE CASE OF THE ANTARTIC BLUE WHALE

• In 1964 the Committee of Three estimated that the
  population would increase by 10 annually an
  annual discount rate of 21 would be enough to
  cause the whalers to prefer extinction to
  conservation.
• The IWC was unable to
• adopt regulations to prevent
• near complete extermination
• of the blue whale.

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THE CASE OF THE ANTARTIC BLUE WHALE

• Fortunatly, in 2003 the IWC suggested that the
  number of Antartic blue whales may have been
  risen from about 500 animals a quarter of a
  century ago to around 1.500 then. The committee
  agreed that there was evidence for an increase in
  blue whales, but without enough time to analyze
  the situation, it was not possible to accept
  specific estimates of abundandce and trends.

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THE AFRICAN ELEPHANT CASE
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THE AFRICAN ELEPHANT

• Elephants are all across Africa
• From Savannahs to rain forests
• Adult male 12.000 pounds
• Social behaviour remains the same
• Adult males leave at the age of 14
• The whole herd prtects the children

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THE AFRICAN ELEPHANT

• Famous for their big ivory tusks
• Problem of poaching
• 1977 1,3 million elephants
• 1997 600.000 remained
• Two big issues Poaching problem and limited
  trade of ivory

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THE AFRICAN ELEPHANTProblems and Solutions

• Increasing population of Africa and lack of land
  to eat
• Ways to keep elephants out of the crops
• Sport Hunting
• Solution Green Hunting
• GPS and fake tusks