Actuaries intuitively feel that positive correlations between individual ri
sks reveal a more dangerous situation compared to independence. The purpose
of this short note is to formalize this natural idea. Specifically, it is
shown that the sum of risks exhibiting a weak form of positive dependence k
nown as positive cumulative dependence is larger in convex order than the c
orresponding sum under the theoretical independence assumption. (C) 2001 El
sevier Science B.V. All rights reserved.