A given amount of stock is to be distributed onto a homogeneous group of consumers. Each of the consumers rates their benefit with the same profit function. We ask for the optimal total profit and the structure of the best distribution. In 1920, the economist DALTON formulated principles on the distribution of incomes. He has proposed convex criterions to mesure its quality, so that the uniformal distribution is the best one. We consider non-convex rating criterions and study the following parametric problem:

The goal function
is symmetric w.r.t. permutations of the variables,
the symmetric partition (uniformal distribution)
is
a stationary solution of this problem. We investigate the structure of the global
minimum
in dependence on the linking parameter c for strictly
convex-concave functions f. Under some additional conditions on f, a branching
between symmetric and non-symmetric sructures can be described. Certain convexity
defect mesures contribute to an explanation of this phenomenon.
Following examples belong to this class of problems:
The below represented figure demonstrates solution structures for the first example. Optimal triple are vertically illustreted.