The paper provides a rigorous derivation of the "welfare triangle approximation" (WTA), which is at the center of cost benefit analysis. The result is generalized by showing that the WTA is one of two dual expressions, one of which approximates the change in real consumption, the other the...

The paper provides a rigorous derivation of the "welfare triangle approximation" (WTA), which is at the center of cost benefit analysis. The result is generalized by showing that the WTA is one of two dual expressions, one of which approximates the change in real consumption, the other the...

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...