The Role of Dominance Hierarchy in the Evolution of Social Species

A number of animal species from different lineages live socially. One of the features of social living is the formation of dominance hierarchy. Despite its obvious benefit in the survival probability of the species, the hierarchical structureitself poses psychological and physiological burden leading to the chronic activation of stress related pathways. Considering these apparently conflicting observations, here we propose that social hierarchy can act as a selective force in the evolution of social species. We also discuss its role on social psychology.     

PRICE‐DEPENDENT INVENTORY MODELS WITH DISCOUNT OFFERS AT RANDOM TIMES*

We consider an inventory model with a supplier offering discounts to a reseller at random epochs. The offer is accepted when the inventory position is lower than a threshold level. We compare three different pricing policies in which demand is induced by the resellers price variation. Policy 1 is the EOQ policy without discount offers. Policy 2 is a uniform price, stock‐independent policy. Policy 3 is a stock level‐dependent, discriminated price policy. Assuming constant demand rates, expressions are obtained for the optimal order quantities, prices, and profits. The numerical experiments show that if it is better to accept a suppliers discount, then it benefits the reseller to transfer the discount to downstream customers.