We estimate the marginal external congestion cost of motor-vehicle travel for Rome, Italy, using a methodology that accounts for hypercongestion (a situation where congestion decreases a road’s throughput). We show that the external cost – even when roads are not hypercongested...

We estimate the marginal external congestion cost of motor-vehicle travel for Rome, Italy, using a methodology that accounts for hypercongestion (a situation where congestion decreases a road's throughput). We show that the external cost - even when roads are not hypercongested - is substantial,...

This article shows that in the presence of environmental externalities, it may be welfare enhancing to overcome a technological lock-in by a dead- end technology through governmental intervention. It is socially desirable to subsidize a dead-end technology if its environmental externality is...

A basic tenet of economics posits that when consumers or firms don't face the true social cost of their actions, market outcomes are inefficient. In the case of negative externalities, Pigouvian taxes are one way to correct this market failure, where the optimal tax leads agents to internalize...