We extend the models in ("Competition in two-sided markets" of Armstrong (2006, Rand Journal of Economics) by adding within-group externalities. In the monopoly and duopoly cases, positive within-group externalities reduce the price of the own group. Negative externalities have an opposite price...

Dams are essential for water storage and hydropower generation, but change river flow patterns and endanger local environments. Dam projects may further exacerbate already existing problems in trans-boundary rivers. We consider three scenarios of institutional factors: (1) each country pursues...