1 / 24

Basic Bioeconomics Model of Fishing

Basic Bioeconomics Model of Fishing. Objectives of lecture. Introduce you to basic bioeconomic analysis; Introduce you to game theoretic applications to the study of shared fish stocks. Catch per unit effort.

nelia
Download Presentation

Basic Bioeconomics Model of Fishing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Basic Bioeconomics Model of Fishing

  2. Objectives of lecture • Introduce you to basic bioeconomic analysis; • Introduce you to game theoretic applications to the study of shared fish stocks.

  3. Catch per unit effort • Catch per unit of fishing effort (CPUE) is the total catch divided by the total amount of effort used to harvest the catch. • CPUE = c/E

  4. Global catch and effort 25 90 80 20 70 60 Catch 15 50 Catch (million tonnes) Effort (GW or watts x 109) 40 10 30 20 5 10 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Year FAO Fisheries Statistics *Effective effort indexed on 2000 based on average 2.42% increase annually

  5. Global catch and effort 25 90 80 20 70 60 Catch 15 50 Catch (million tonnes) Effort (GW or watts x 109) 40 10 30 20 5 Effective effort* 10 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Year Watson et al. (2012) *Effective effort indexed on 2000 based on average 2.42% increase annually

  6. Classical Management Problems • Overfishing; • Overcapacity; • Low or negative profits. • Can you predict the above using only cpue and/or fishing mortality models? Nope! • Bioeconomic models needed to predict these results!

  7. These undesirable outcomes are the result of Individually Rational, but Non-cooperative Behavior

  8. Issues in fisheries economics • Fish as natural capital in a broad sense; • Fish as common property resource; • Externalities  Tragedy of the commons   Private property; • Need for regulation; • Decision making over time.

  9. Fish as natural capital in a broad sense • The natural environment contains the natural resources essential to life on earth; • Natural resources provide inputs to our economic system; • By and large economists see natural resources as similar to human made capital.

  10. Economic efficiency and Bioeconomics

  11. Economic efficiency • Maximum profit subject to sustainability; • Profit = Total Revenue – Total Cost; • With economic efficiency, profit is maximized.

  12. A static single species model • Fisheries biology – the logistic model; • The optimal harvest – equilibrium catch; • The maximum sustainable yield; • Sustainable yield as a function of effort; • Max Profit= max(TR-TC):=Maximum Economic Yield; • Profit=TR-TC=0:=Bionomic equilibrium.

  13. MSY Bionomic equilibrium (BE) Total cost of fishing effort (TC) MEY TR & TC ( $) Max. rent Total Revenue (TR) E1 E2 E3 Fishing effort (E) The Basic Bioeconomic model Gordon Schaefer bioeconomic model

  14. Bioeconomic Models • (1) Biological Model: Net annual change of biomass = Growth + Recruitment – Nat. Mortality – Catch (2) Economic Model: Net annual revenue = Sales income - Cost

  15. R = pH – cE Schaefer Catch Equation: H = qEx (Highly Dubious!) Therefore R = (pqx – c) E Bionomic Equilibrium: Under open access, fishery reduces the stock level x until R = 0, i.e., x = c/pq Predictions: Zero rents; overfishing ( if c/p low).

  16. Numerical example: Bo = 1,000,000 t q = .001 / vessel yr c = $ 500,000 / vessel yr Price p ($/tonne) x (Bionomic Eq.) 500 1,000,000 t 1,000 500,000 t 5,000 100,000 t What is Bionomic Equilibrium?

  17. How to Fix It? • TACs? • Gear Regulations? • Limited Entry? • Vessel Buy-backs? • Quasi-property rights through individualized (or community) quotas; • MPAs; • Taxes.

  18. Bioeconomic modeling • The objective of fisheries management: • Conservation of resources through time; • Economic viability and profitability; • Social objectives.

  19. Economic rent/profit • Total revenue = price*harvest (V). • Total cost = unit cost of effort* effort (C). • Economic rent = V – C.

  20. Dynamic bioeconomic model • Discounted economic rent (V-C) through time to obtain the discounted value of the economic benefits from the fishery.

  21. Decision making over time • Natural resource (NR) use involves decision making over time: • How much oil or gold should be extracted from a mine this year, how much next year, etc? • Should salmon on the west coast of Canada be harvested intensively this year or not at all? • Time is important because the supply curve of NRs are always shifting due to: • Depletion of non-renewable resources and • biological and physical changes in renewable resources.

  22. Hence, a dynamic rather than a static analysis is required to analyze natural resource use in most cases; • Interest or discount rates are a crucial link between periods in dynamic models of NR use; • Discount rate vs. discount factor; • Present value vs. current value. • Introduce your quiz!

  23. Thank for your attention

More Related