Contrary to system costs, however, they do possess their own, if rather limited, constituencies that ensure that they are taken into account at least in a partial, if imperfect internalisation process. The complexity and duration of the process makes covering, reporting, disseminating and absorbing the relevant information much more difficult. An accident with 50 fatalities once every ten years will get infinitely more media and policy attention than 1 000 premature deaths coupled with increased morbidity in a large population because of a constant level of pollution over the same time span. While individual human suffering cannot be calculated and compared, dispassionate reflection with an aim to improve general welfare would suggest that the far larger number of casualties due to air pollution would demand at least as much attention as rare accidents.