1 / 10

AGEC/FNR 406

AGEC/FNR 406. AGEC/FNR 406. LECTURE 29. LECTURE 26. Catch of the day, Palawan. Fishery Economics, Part 1. Characteristics of Fisheries 1. Renewable natural resource 2. Interactive (stock effects and feedbacks are important) 3. Usually open-access property (more on this later).

onawa
Download Presentation

AGEC/FNR 406

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. AGEC/FNR 406 AGEC/FNR 406 LECTURE 29 LECTURE 26 Catch of the day, Palawan

  2. Fishery Economics, Part 1 Characteristics of Fisheries 1. Renewable natural resource 2. Interactive(stock effects and feedbacks are important) 3. Usually open-access property (more on this later)

  3. Apply what you already know: 1. Goal: maximize net benefits marginal condition for static efficiency MC = MB complication is defining cost and benefit functions 2. Property rights structure Open-access or common property in most cases rent is dissipated (know what this means) intervention necessary for efficiency

  4. Interactive (feedbacks) Size of population depends on: 1. Biological factors Habitat Size Quality - amount of pollution Food supply 2. Actions of society Harvest levels

  5. Basic interactive model Define variables: Xt  stock (population) at time t X0  initial stocking level Gt  growth during tth time period (function of Xt) Ct catch level during tth time period

  6. Interactive model Stocking level at end of 1st time period is, X1 = Xo + G1 (Xo) - C1 And, in general, Xt = Xt-1 + Gt (Xt-1) - Ct

  7. Simplified Growth Model Growth is a function of stock: Gt (Xt-1) Stock is measured as a level (e.g. principal) Growth is a flow (e.g. interest) But growth is complicated: Q: With more stock is growth slower or faster? A: It depends on the level of stock

  8. Logistic Growth Function(see Kahn, figure 10.1) G2 Growth of population (G) G1 X1 K X2 Fish population (X)

  9. Interpretation of Growth Function Minimum viable population: X0 Population less than X0 will become extinct Natural equilibrium (carrying capacity): K Largest population habitat can support Growth equal to mortality Maximum sustainable yield: MSYMSY stock: XMSY Harvest level equal to growth level MSY harvest (yield): CMSY

  10. Critical depensation(Kahn, Figure 10.3) CMSY Growth (G) XMSY X0 K Population (X)

More Related