Economies of Scale and Scope in Railroading
Prof. Ron Yang
Assistant Professor in Strategy and Business Economics
University of British Columbia
To what extent do transportation costs depend on the amount shipped, and how does infrastructure investment shape these costs? We model railroads as multiproduct firms and estimate the link between capacity utilization and costs using firm choices, the network structure of production, and publicly available routing data. We find a U-shaped relationship between marginal costs and rail utilization: As utilization increases, costs decrease by 30% to a low point at 55% utilization, before increasing by another 30%. Increased congestion in the rail network can explain a third of the 50% increase in real rail prices observed since 2004. We use our framework to estimate the network externalities of rail infrastructure investment, finding that investment in Arizona provides the highest returns, but only 3% are captured by Arizona itself.