On the social desirability of urban rail transit systems

Despite a decline in its mode share, investment to build new urban rail transit systems and extend old ones continues. We estimate the contribution of each U.S. urban rail operation to social welfare based on the demand for and cost of its service. We find that with the exception of BART in the San Francisco Bay area, every system actually reduces welfare and is unable to become socially desirable even with optimal pricing or physical restructuring of its network. We conclude rail's social cost is unlikely to abate because it enjoys powerful political support from planners, civic boosters, and policymakers.