This paper derives a three stage Cournotoligopoly game for product innovation, expenditure on introducing the product and competition on the product market. Product innovation is assumed to increase consumer utility but is effective only if the innovating firm invests in marketing, so that...

This paper introduces a number of game-theoretic tools to model collusive agreements among firms in vertically differentiated markets. I firstly review some classical literature on collusion between two firms producing goods of exogenous different qualities. I then extend the analysis to a...