fish stock
catch per year
with a quota
–
total catch, 40 yrs (kt)
–
stock left at year 40
–
catch per boat, year 40 (kt)
Everyone for themselves
Agreed quota
Boats
30
Catch each boat wants per year
4.0 kt
Replay 40 years
Different weather
Logistic growth: a stock of 1,000 thousand tonnes (kt) can produce at most 100 kt of new fish a year, at half size. The dashed line shows what the other rule would do with the same fleet and the same weather. Stock and catch share the same scale.