Policymakers all over the world claim: no innovation without protection. For more than a century, critics have objected that the case for intellectual property is far from clear. This paper uses a game theoretic model to organise the debate. It is possible to model innovation as a prisoner's...

Two suppliers of a homogenous good know that, in the second period, they will be able to collude. Gains from collusion are split according to the Nash bargaining solution. In the first period, either of them is able to invest into process innovation. Innovation changes the status quo pay-off,...