caa a22 4500 445890568 CHVBK 20180317145615.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s11116-010-9310-0 doi (NATIONALLICENCE)springer-10.1007/s11116-010-9310-0 Estimating the agglomeration benefits of transport investments: some tests for stability [Elektronische Daten] [Daniel Graham, Kurt Dender] The case for including agglomeration benefits within transport appraisal rests on an assumed causality between access to economic mass and productivity. Such causality is justified by the theory of agglomeration, but is difficult to establish empirically because estimates may be subject to sources of bias from endogeneity and confounding. The paper shows that conventional panel methods used to address these problems are unreliable due to the highly persistent nature of accessibility measures. Adopting an alternative approach, by applying semiparametric techniques to restricted sub-samples of the data, we find considerable nonlinearity in the relationship between accessibility and productivity with no positive effect to be discerned over broad ranges of the data. A key conclusion is that we are unable to distinguish the role of accessibility from other potential explanations for productivity increases. For transport appraisal, this implies that the use of conventional point elasticity estimates could be highly misleading. Springer Science+Business Media, LLC., 2010 Agglomeration nationallicence Transport nationallicence Causality nationallicence Heterogeneity nationallicence Confounding nationallicence Graham Daniel Centre for Transport Studies, Imperial College London, SW7 2AZ, London, UK aut Dender Kurt Joint Transport Research Centre of the OECD and the International Transport Forum, Paris, France aut Transportation Springer US; http://www.springer-ny.com 38/3(2011-05-01), 409-426 0049-4488 38:3<409 2011 38 11116 https://doi.org/10.1007/s11116-010-9310-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11116-010-9310-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Graham Daniel Centre for Transport Studies, Imperial College London, SW7 2AZ, London, UK aut NATIONALLICENCE 700 1- Dender Kurt Joint Transport Research Centre of the OECD and the International Transport Forum, Paris, France aut NATIONALLICENCE 773 0- Transportation Springer US; http://www.springer-ny.com 38/3(2011-05-01), 409-426 0049-4488 38:3<409 2011 38 11116 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer