We analyze duopoly Bertrand competition under network effects. We consider both incompatible and compatible products. Our main result is that network effects create a fundamental conflict between the maximization of social welfare and consumer surplus whenever products are incompatible. While...

This paper proposes a model for a certification market with an imperfect testing technology. Such a technology only assures that whenever two products are tested the higher quality product is more likely to pass than the lower quality one. When only one certifier with such testing technology is...