### 4.5.1 Revised assumptions

As you have noticed we have not yet built harvesting into the logistic model.

Assume that the birth-rate and death-rate are linear with respect to the population size as it was in the previous step of iteration. About harvesting we assume that the harvesting rate h is constant. Evidently, this assumption is an approximate one because catching of fishes is mor effective if there are more fishes in the sea. However, it is quite difficult to state the exact relationship between the harvesting rate and population size of fishes.