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- Börjesson, Maria, 1974-, et al.
(author)
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Catching the tail : Empirical identification of the distribution of the value of travel time
- 2012
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In: Transportation Research Part A. - : Elsevier BV. - 0965-8564 .- 1879-2375. ; 46:2, s. 378-391
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Journal article (peer-reviewed)abstract
- Recent methodological advances in discrete choice analysis in combination with certain stated choice experiments have allowed researchers to check empirically the identification of the distribution of latent variables such as the value of travel time (VTT). Lack of identification is likely to be common and the consequences are severe. E.g., the Danish value of time study found the 15% right tail of the VTT distribution to be unidentified, making it impossible to estimate the mean VTT without resorting to strong assumptions with equally strong impact on the resulting estimate. This paper analyses data generated from a similar choice experiment undertaken in Sweden during 2007–2008 in which the range of trade-off values between time and money was significantly increased relative to the Danish experiment. The results show that this change allowed empirical identification of effectively the entire VTT distribution. In addition to informing the design of future choice experiments, the results are also of interest as a validity test of the stated choice methodology. Failure in identifying the right tail of the VTT would have made it difficult to maintain that respondents’ behaviour is consistent with utility maximisation in the sense intended by the experimenter.
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- Börjesson, Maria, 1974-, et al.
(author)
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On the income elasticity of the value of travel time
- 2012
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In: Transportation Research Part A. - : Pergamon Press. - 0965-8564 .- 1879-2375. ; 46:2, s. 368-377
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Journal article (peer-reviewed)abstract
- Transport infrastructure is long-term and in appraisal it is necessary to value travel time savings for future years. This requires knowing how the value of time (VTT) will develop over time as incomes grow. This paper investigates if the cross-sectional income elasticity of the VTT is equal to inter-temporal income elasticity. The study is based on two identical stated choice experiments conducted with a 13. year interval. Results indicate that the relationship between income and the VTT in the cross-section has remained unchanged over time. As a consequence, the inter-temporal income elasticity of the VTT can be predicted based on cross-sectional income elasticity. However, the income elasticity of the VTT is not a constant but increases with income. For this reason, the average income elasticity of the VTT in the cross-sections has increased between the two survey years and can be expected to increase further over time.
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- Börjesson, Maria, 1974-, et al.
(author)
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Response time patterns in a stated choice experiment
- 2015
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In: Journal of Choice Modelling. - : Elsevier BV. - 1755-5345. ; 14, s. 48-58
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Journal article (peer-reviewed)abstract
- This paper studies how response times vary between unlabelled binary choice occasions in a stated choice (SC) experiment, with alternatives differing with respect to in-vehicle travel time and travel cost. The pattern of response times is interpreted as an indicator of the cognitive processes employed by the respondents when making their choices. We find clear signs of reference-dependence in response times in the form of a strong gain-loss asymmetry. Moreover, different patterns of response times for travel time and travel cost indicate that these attributes are processed in different ways by respondents. This may be of particular relevance for choice experiments in the transportation field, where the travel time attribute is central.
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- Börjesson, Maria, 1974-, et al.
(author)
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The income elasticity of the value of travel time is not one number
- 2009
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In: Proceedings of the European Transport Conference. - : Association for European Transport.
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Conference paper (peer-reviewed)abstract
- This paper provides new evidence on the evolution of the value of travel time (VTT) over time and its relation to income based on two essentially identical Stated Choice experiments conducted at an interval of 13 years. The results indicate that the income elasticity of the VTT is not uniform over income but increasing in income. As a consequence, the average rate at which the VTT increases with income in the cross-sectional samples has itself increased between the two survey years and can be expected to increase further over time. The estimation results support the idea that the income elasticity of the value of time has remained constant at each real income level. This confirms that it is not so much the relationship between income and the value of travel time that has changed over time as it is the level and distribution of income in the samples that has changed.
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| 7. |
- De Borger, Bruno, et al.
(author)
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Information provision by regulated public transport companies
- 2012
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In: Transportation Research Part B. - : Elsevier BV. - 0191-2615 .- 1879-2367. ; 46:4, s. 492-510
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Journal article (peer-reviewed)abstract
- We study the interaction between pricing, frequency of service and information provision by public transport firms offering scheduled services, and we do so under various regulatory regimes. The model assumes that users can come to the bus stop or rail station at random or they can plan their trips; the fraction of users who plan their trips is endogenous and depends on the frequency of service and on the quality of information provided. Four institutional regimes are considered, reflecting various degrees of government regulation. A numerical example illustrates the theoretical results. Findings include the following. First, fare regulation induces the firm to provide less frequency and less information than is socially optimal. Second, if information and frequency did not affect the number of planning users a higher fare always induces the firm to raise both frequency and the quality of information. With endogenous planning, however, this need not be the case, as the effect of higher fares strongly depends on how frequency and information quality affect the number of planners. Third, a profit-maximizing firm offers more information than a fare-regulated firm. Fourth, if the agency regulates both the fare and the quality of information then more stringent information requirements induce the firm to reduce frequency; this strongly limits the welfare improvement of information regulation. Finally, of all institutional structures considered, socially optimal fares, frequency and quality of information stimulate passengers least to plan their trips, because the high frequency offered reduces the benefits of trip planning.
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| 8. |
- Eliasson, Jonas, et al.
(author)
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Cost-benefit analysis of transport improvements in the presence of spillovers, matching and an income tax
- 2019
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In: Economics of Transportation. - : Elsevier BV. - 2212-0122 .- 2212-0130. ; 18, s. 1-9
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Journal article (peer-reviewed)abstract
- This paper addresses the problem of measuring the welfare benefits of a transport improvement. We formulate and analyze a rich spatial model that allows for spillovers, matching and income tax, in a setting with multiple work and residential locations and very general worker heterogeneity. The conventional consumer surplus captures part of the benefits and is calculated based on predictions of changes in travel demand and transport costs. The issue is to determine which so-called wider impacts to add to this. We find that adding the change in total output as a wider impact leads to double-counting of benefits. The output change due to spillovers should be added, while the output change due to matching is already partly included in the consumer surplus. These results are useful for applied cost-benefit analysis of transport policies
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| 9. |
- Eliasson, Jonas, et al.
(author)
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Cost overruns and demand shortfalls - Deception or selection?
- 2013
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In: Transportation Research Part B. - : Elsevier BV. - 0191-2615 .- 1879-2367. ; 57, s. 105-113
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Journal article (peer-reviewed)abstract
- A number of highly cited papers by Flyvbjerg and associates have shown that ex ante infrastructure appraisals tend to be overly optimistic. Ex post evaluations indicate a bias where investment costs are higher and benefits lower on average than predicted ex ante. These authors argue that the bias must be attributed to intentional misrepresentation by project developers. This paper shows that the bias may arise simply as a selection bias, without there being any bias at all in predictions ex ante, and that such a bias is bound to arise whenever ex ante predictions are related to the decisions whether to implement projects. Using a database of projects we present examples indicating that the selection bias may be substantial. The examples also indicate that benefit-cost ratios remain a useful selection criterion even when cost and benefits are highly uncertain, gainsaying the argument that such uncertainties render cost-benefit analyses useless.
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