Modelling the effects of population aggregation on the efficiency of insect pest control

Summary A methodology is developed to assess the effects of spatial distribution on the efficiency of insect pest control. This methodology is especially applicable to pest control methods whose efficiency of action depends either positively or negatively on pest density It is applied here to the sterile insect technique and pheromone trapping for male annihilation, which both depend negatively on density. This methodology relies on quantifying clumps of various size and then relating this to efficiency of control and predicting the total pest production given the information on clump sizes and efficiency of control for each clump size. It is found that control is about four times as difficult for a population that is highly clumped (k of the negative binomial distribution=0.25) as for a regularly dispersed population.     

Dread risks

It is a well-established fact that many people view the prospect of premature death by some causes with considerably more disquiet or “dread” than death by other causes. It is equally clear that for most people their personal risk of death by a given cause is also a matter of serious concern. This article reports the findings of a study aimed at estimating the effects of dread and personal risk of death by a specific cause on the willingness-to-pay based Value of Statistical Life (VSL) for that cause. JEL Classification J17