In their stimulating and thought-provoking paper, Caulkins, Reuter & Coulsen  argue that ratings of harm by drugs provide, at best, very incomplete information basis for decisions on scheduling various substances, and furthermore they challenge the idea that it is possible to create a ‘perfect, objective, evidence-based composite measure’ of a drug's harms. In line with some previous publications in this area (e.g. [2–4]), the authors provide good arguments as to why it is problematic to apply a single-dimension harm scale. Consequently, one may ask whether this means that ratings of the relative harm from various drugs are useless. Caulkins et al. do not entirely dismiss the usefulness of such comparisons, but their discussion is related mainly to that of policy decisions on whether or not to ban specific harmful substances. This is much in line with how the applicability of such harm rankings have been discussed in previous works [5–7]. While Caulkins et al. noted that decisions on prohibiting (‘scheduling’) substances are the most fundamental policy decisions, I will argue that other types of policy decisions and related debates are also highly relevant in this respect.
In Norway, two of the larger political parties have, over many years, favoured more restrictive policies with respect to illicit drugs and also favoured liberalization of alcohol control policies, on the grounds that they regard both illicit drug abuse and related problems as a significantly larger problem for society than alcohol-related problems. This view reflects a widely held opinion in the general population in Norway: more than half the respondents in surveys agree with the statement that it is ‘narcotic drugs that the authorities should do something about, not alcohol’. Similar views are probably held by policy makers and the public in many other countries as well. For instance, in the United States, respondents in national surveys have been asked to identify the single most important problem facing the country, and for several years the category ‘drugs’ has been ranked among the top five single most important problems .
However, when turning to the views of scholars in the field, these may well find that it is the legal substances, rather than illicit drugs, that cause most harm to society in most countries . This is clearly the case with respect to the health burden attributable to addictive substances, for which tobacco and alcohol's toll is much larger than that of illicit drugs . Also, with respect to violent crimes  and economic costs , alcohol seems to account for a larger proportion of the burden compared to illicit drugs.
Although one could imagine that other aspects of harm weigh more heavily than health, violence and economic costs in the eyes of policy makers and the public, it seems more likely that their views are based on limited and biased information. In line with this, Room & Lubman  noted that the absence of alcohol and tobacco from current classifications of drugs ‘. . . . provide a “scientific” rationale for governments to justify a hardline approach to illicit drugs while downplaying the need for effective evidence-based policies to licit substances’.
Given that a broader purpose of comparing and rating harms from various substances is to inform efforts to reduce total harm as much as possible, it may therefore be useful to inform policy makers and the public about the relative importance of licit drugs (including prescription drugs) and illicit drugs for various types of harm.