01660551

Component

The objective of this study is to give an overview about the different accessibility met rics used in agglomeration elasticity estimations. New data sources from Highway England make it possible to create new accessibility metrics, which use actual observed journey times and thus can explicitly control for negative externalities arising from traffic congestion. The authors' findings show the importance of finding the right accessibility metric, as estimated elasticities can differ two-three fold. After estimating total factor productivity for every firm in England between 2009 and 2015, using the FAME dataset, the authors calculate Mean Effective Density for every Middle Super Output Area. In a two-step method, the authors estimate agglomeration elasticities, using the Generalised Method of Moments methodology. Results show that the most important step is incorporating not just the distance, but also the time dimension of effective density (journey times). This suggests the importance of traffic congestion in reducing effective density and thus leading to a loss in wider economic benefits arising from transportation. The authors' results also suggest that different sectors of the economy value accessibility differently.

This paper was sponsored by TRB committee ABE30 Standing Committee on Transportation Issues in Major Cities. Alternate title: Firms, Agglomeration, and Congestion: Comparing the Impacts of Different Measures of Accessibility on Productivity

18-05231

English

19p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; Maps; References; Tables

Accessibility; Economic impacts; Metrics (Quantitative assessment); Productivity; Traffic congestion; Travel time

Agglomeration

England

Economics; Highways; Planning and Forecasting

Transportation Research Board Annual Meeting 2018 Paper #18-05231

TRIS, TRB, ATRI

Jan 8 2018 11:19AM