Following models of vertically differentiated duopoly this paper deals with the influence of a social health system on the sustainability of the duopoly and on the respective prices. Emphasis is laid on the effect of a reduction of the coinsurance rate for drugs on prices and on the market...

Group Purchasing Organizations (GPOs) increasingly gain in importance with respect to the supply of pharmaceutical products and frequently use multiple or exclusive rebate contracts to exercise market power. Based on a Hotelling model of horizontal and vertical product differentiation, we...