Increasing accessibility by public transport benefits local economy: the effect of a new metro line in Rome

2025-10-01

AI Summary

This study examines the causal impact of Rome Metro Line C’s opening on local economic activity, focusing on how improved transport accessibility affects economic density, industrial diversity, and microenterprise employment and GDP. Employing a difference-in-differences (DID) framework augmented with a multiplicative model for robust causal identification—and complemented by spatial association analysis—the study finds that metro access significantly increases aggregate economic activity near stations, yet reduces industrial diversity slightly, suggesting spatial agglomeration of similar firms. Microenterprises exhibit disproportionately strong gains in both employment and GDP. As the first systematic, causally identified analysis of rail infrastructure effects on microeconomic agents in a Southern European megacity, this research provides rigorous empirical support for transit-oriented development (TOD) policies and yields generalizable insights into heterogeneous impacts of public transport investment on local economic structures.

Technology Category

• Application Domains: Transportation
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Evaluation and Analysis

Application Category

• Web Mining and Content Analysis: Robustness and generalizability of Web mining methods
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work
• Security and Privacy: Large-scale security measurements

Abstract

This study investigates the economic impact of Metro C, a major expansion of Rome's metro system. Using a difference-in-differences (DID) approach within a multiplicative framework, the research quantifies the impact of increased accessibility on local economic activities. The results show a statistically significant rise in the number of economic activities in areas affected by the new line. A mild decline in economic diversity suggests the emergence of spatial clustering of similar activities. A dedicated analysis of microenterprises, which represent the majority of the dataset, examines changes in employment and GDP associated with the new infrastructure. The observed zone-level correlation between accessibility gains and growth in economic activities also offers a basis for generalising the findings beyond the specific case of Metro C. Overall, the case study shows that public transport investments aimed at boosting sustainable mobility can also generate positive spillover effects on the local economic fabric.

Problem

• Evaluating economic impacts of new metro line expansion
• Measuring accessibility effects on local business activities
• Analyzing spatial clustering and microenterprise employment changes

Innovation

• Difference-in-differences approach quantifies metro accessibility impact
• Analysis reveals spatial clustering through economic diversity decline
• Microenterprise examination links infrastructure to employment and GDP