ABSTRACT
ABSTRACT The properties of a relatively new functional, [Becker and Utev (1998)], are investigated, with emphasis on rxtrenie values with respect to a probability distribution. Scale irlvariance is established and degenerate distrihtions are shown to givc extreme valucs. Thc functional gives, for ;t certain strategy of vaccination, the frixction of the householcls that must be immunized to prevent epidemics within a corrmlur~ity consisting of a large nurnl~er of lriouseholds. Interest lies in seeing how the distribution of household size affects the estimatc of the critical immunity coverage. The functional also gives the fraction of indivitluals that must be immunized to prevent cpidemics in a community of individuals who mix uniformly hut whose susceptibility is age-specific. Interest then lies in seeing how the distribution of susceptibility affects the estimate of the critical irnmunity coverage.
