An Open-Access Fishery
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- Each of a number of fishing fleets fishes in an area
- Each season, each fleet chooses how many fish to catch
- The fish remaining at the end of season grows before next season starts
- Fish-stock growth depends on number of remaining fish
- Low growth when stock is either very low or near area's capacity
- The smaller the fish stock, the more costly it is to catch fish
- Your catch depends on both your effort level and the current fish stock
- higher effort increases both your catch and your costs
- Each round, use the slider to choose an effort level from 0 to 100
- Graph shows profits for each possible effort level
- Click Submit to submit chosen effort level
- Your profit for a season is your revenue minus your costs
$${\small \text{Revenue}=$5\times\text{Your Catch}=$5\times(\frac{\text{Fish Stock}}{\text{Area Capacity}}\times \text{Your Capacity}\times\frac{\text{Your Effort}}{100}})$$ $${\small \text{Your Cost}=80 \times \text{Your Effort}^2 - 50 \times \text{Your
Effort}}$$
- Current Fish Stock = 300,000; Area Capacity = 900,000
- Your Capacity = 250,000
- You choose Effort = 27
$${\small \text{Catch}=\frac{300,000}{900,000}\times 250,000 \times\frac{27}{100}=22,500}$$ $${\small \text{Revenue}=$5 \times \text{Catch}=\$112,500}$$ $${\small \text{Your Cost}=80 \times 27^2 - 50 \times 27 = \$56,970}$$ $${\small \text{Revenue}-\text{Costs}=\$55,530}$$