Fisheries

Question 1

Fisheries

Answer 1

open access
stock size can grow
property rights are incomplete
want to calculate the size and timing of an efficient harvest

Question 2

Logistic growth/sustainable yield curve

Answer 2

schaefer logistic model
describes incremental growth in a fish stock as a function of the size of the stock
curve is bell shaped - to the left the stock is increasing at a decreasing rate
peak (where stock is maximised) maximum sustainable yield
to the right the stock size is decreasing due to overcrowding in the water or competition
K is the carrying capacity where mortality is offset by births
G(s) = g0 * S * (1-S/K)

Question 3

Steady-state model

Answer 3

this is the long run equilibrium
fish population remains the same (harvest = net growth)
can maintain any of the population size between x and k on the graph (the natural change from last year)
the maximum sustainable yield is the maximum average level of growth and largest catch that can be perpetually maintained if the stock is reduced beyond this point the stock is overfished

Question 4

Graph of yield effort function

Answer 4

shows total costs and benefits
fishing effort to the left to right, fish stock decreases (more fish, less stock)
Y(E) = returns to fishing effort
after the peak efforts increase while returns decline
always economically overfished before biologically
does not account for time value of money
stock may collapse completely

Question 5

Open access

Answer 5

fisheries are open access
boats will enter as long as rents are positive
profits remain positive and they are breaking even until Eoa where TB = TC here is past the efficient number of boats the rents have disappeared and the fish are depleting
no individual fisherman has the incentive to account for the externality of the depleting fish stock
an example of tragedy of the commons
e.g. herring in the north sea

Question 6

Elinor Ostrom

Answer 6

claims that open access and common property are different 
open access lacks any restriction (dinner with strangers)
common property (dinner with friends)

Question 7

Types of fishery regulation

Answer 7

cost effectiveness - the least costly allocation (the more varied the costs of fishing effort, the greater the saving)
IFQ - regulator sets a specific TAC typically by weight and these can be traded should maximise economic profits
IFQ establishes clear property rights
IFQ changes investment incentives - effort should encompass capital expenditures on boats e.g. gear size

Question 8

Regulations

Answer 8

increase real cost of fishing - gear size limitations this decreases effort
biological - TAC/area closures - places a limit on quantity, doesn’t prevent new entries, no economic profits
licensing - difficults
taxes - profits transferred to government
IFQ - set TAC, can be bought sold or leased, should maximise economic profits