Question

How to illustrate the biological model (Schaefer model) that represents the relationship between the growth of the fish population and the size of the fish population on the graph? What’s the static efficient sustainable yield?

Answer 1

Biological Dimension—The Schaefer model

•The Schaefer model posits an average relationship between the growth of the fish population and the size of the fish population.

•The shape of the graph shows the range of population sizes where population growth leads to population increases and a range where population growth will lead to stock decreases.

Relationship between the Fish Population and Growth:

Static Efficient Sustainable Yield :

•The static-efficient sustainable yield is the catch level that, if maintained perpetually, would produce the largest annual net benefit.

•Assumptions of the economic model are:

¨The price of fish is constant and does not depend on the amount sold.

¨The marginal cost of a unit of fishing effort is constant.

¨The amount of fish caught per unit of effort expended is proportional to the size of the fish population.

•The static-efficient sustainable yield allocation maximizes the constant net benefit.

Efficient Sustainable Yield for a Fishery (graph)