L'évaluation socioéconomique des investissements publics

Le rapport L'évaluation socioéconomique des investissements publics confié à Emile Quinet par le Commissariat général à la stratégie et à la prospective met à jour et enrichit la méthodologie d'évaluation socioéconomique des investissements publics, étudie les conditions d'une bonne appropriation de ses résultats par les décideurs, et étend le calcul socioéconomique au-delà de ses champs d'application traditionnels que sont les transports et l'énergie. En cette période de fortes contraintes budgétaires, probablement amenée à se prolonger dans les années à venir, il est plus que jamais nécessaire de rationaliser les dépenses publiques, qu'elles soient de fonctionnement ou d'investissement. Les dépenses publiques d'investissement représentent environ 15 % des investissements totaux de notre pays. Elles concernent des secteurs aussi essentiels pour le développement de notre société que les transports, l'énergie, la santé ou l'éducation. Ces investissements façonneront sur le long terme, parfois pour plusieurs siècles, l'aspect de notre pays, la qualité de son environnement, sa capacité à affronter les défis futurs. C'est dire combien les décisions doivent être prises de la façon la plus éclairée possible, en évaluant au mieux les avantages qu'ils vont procurer et les coûts qu'ils vont engendrer, d'autant que leur financement repose en large partie sur l'épargne publique nationale, ressource rare en général et encore plus dans la période actuelle. Ce n'est donc pas sans raison que l'État s'est préoccupé depuis longtemps d'élaborer et de mettre régulièrement à jour les méthodes permettant d'assurer ces évaluations. La commission qui a réalisé les travaux présentés dans ce rapport L'évaluation socioéconomique des investissements publics se situe dans la lignée d'une longue tradition, initiée par les rapports établis par Marcel Boiteux en 1994 et 2001. Ces rapports ont fixé la doctrine générale et ont permis des avancées sur des sujets particuliers : le taux d'actualisation, la prise en compte du risque, la valeur tutélaire du carbone. Les principes sur lesquels elle s'appuie sont simples et de construction ancienne. Ils consistent à jauger les conséquences de chaque projet sur l'ensemble de la collectivité nationale, en évaluant les gains de productivité ou de capacité de production apportés aux entreprises ainsi que les suppléments de consommation marchande et les améliorations de qualité de vie procurés aux citoyens, et en permettant de comparer ces effets aux coûts de l'investissement. - See more at: http://www.strategie.gouv.fr/publications/levaluation-socioeconomique-investissements-publics-tome1#sthash.YjQcZR3S.dpu

Forecasting the demand for privatized transport - What economic regulators should know, and why

Forecasting has long been a challenge, and will remain so for the foreseeable future. But the analytical instruments and data processing capabilities available through the latest technology, and software, should allow much better forecasting than transport ministries, or regulatory agencies typically observe. Privatization brings new needs for demand forecasting. More attention is paid to risk under privatization, than when investments are publicly financed. And regulators must be able to judge traffic studies done by operators, and to learn what strategic behavior influenced these studies. Many governments, and regulators avoid good demand, modeling out of lack of conviction that theory, and models can do better than the"old hands"of the sector. This is dangerous when privatization changes the nature of business. For projects amounting to investments of $100-200 million, a cost of$ 100,000-200,000 is not a reason to reject a reasonable modeling effort. And some private forecasting firms are willing to sell guarantees, or insurance with their forecasts, to cover significant gaps between forecasts, and reality.Markets and Market Access,Environmental Economics&Policies,Economic Theory&Research,Decentralization,Banks&Banking Reform,Markets and Market Access,Economic Theory&Research,Banks&Banking Reform,Access to Markets,Environmental Economics&Policies

Effect of imperfect competition on infrastructure charges

The text explores the optimal infrastructure charges of an unbundled activity where the infrastructure manager sells the use of the infrastructure to operators providing services to a downstream market made up of atomistic customers. This situation has been widely analysed under the assumption that the upstream market is competitive, but more rarely in the case of imperfect competition. Typical examples are the railways activity in Europe and air transport. Various market structures are considered, illustrated by situations encountered in the transport field: a single mode operated by a single operator, two operators competing within the same mode, and two modes competing in a Bertrand way. In each case, situations are analysed using analytic formulae with a simplified demand function and a simplified cost function, and performing simulations with sensible parameter values drawn from current average situations. The main result is that the analysed imperfections make a dramatic departure from the conventional Marginal Cost pricing doctrine. Conclusions are drawn regarding infrastructure charging policy

Track wear-and-tear cost by traffic class: Functional form, zero output levels and marginal cost pricing recovery on the French rail network

We address the issue of the allocation of railway track maintenance (wear-and-tear) costs to traffic output classes and consider a very general function relating maintenance cost C to a set of technical production characteristics K used to produce traffic output vector T. We neglect other rail cost categories, such as traffic control and track renewal. The data base pertains to over 1500 sections of the French rail infrastructure in 1999, representing about 90% of the total network of 30000 km of lines in regular service. In addition to the maintenance cost C, it provides by track section 15 technical characteristics (both state S and quality Q) and 4 train traffic outputs T. Input prices, assumed to be uniform in space, disappear from the analysis, as in other national cross-sectional cases. With database subsets of approximately 1000 observations, several functional forms are tested: Linear, Log-Log, trans-Log and generalized Box-Cox. All are embedded in an unrestricted extension (U-GBC) of Khaled's seminal restricted generalized Box-Cox (R-GBC) functional specification. The U-GBC architecture, compared with its 4 principal nested variants, turns out to be by far the most appropriate, in particular when some observed zero traffic sample values are included - an issue rather neglected previously in the literature. It appears that several technical characteristics, such as maximum allowed speed and number of switches, are highly significant maintenance cost factors, which gives a hint that derived marginal costs are short term; also, the relation between maintenance costs and traffic is non linear and differs significantly by train category. Implications of different specifications for marginal infrastructure cost charges by traffic type are outlined.Ce texte traite de l'allocation des coûts d'entretien de l'infrastructure ferroviaire, entendus au sens de "coûts à périodicité annuelle", aux divers types de trafic. Sont exclus de l'analyse les coûts de circulation (contrôle du trafic) et de renouvellement des voies dits "coût de régénération". La fonction de coût utilisée, très générale, relie le coût C à un ensemble de caractéristiques techniques K et à un vecteur de produits T. Les données utilisées proviennent d'une base de données relative à la France sur une décomposition en 1500 segments environ d'un réseau ferroviaire de 30000 km de lignes en service en 1999. On dispose par segment, en plus du coût d'entretien C, de leurs 15 principales caractéristiques techniques (tant d'état S que de qualité Q) et du trafic T décomposé en 4 catégories de service. Les prix, supposés constants à travers le pays, disparaissent de l'analyse, à l'instar d'autres exemples construits à partir de coupes transversales nationales. A partir de sous-ensembles d'approximativement 1000 observations, différentes spécifications de relations fonctionnelles sont testées et évaluées : linéaire, Log-Log, trans-Log et Box-Cox généralisée. Elles sont toutes comprises dans un prolongement non contraint (U-GBC) de la formulation fondatrice Box-Cox généralisée contrainte (R-GBC) de Khaled. La structure générale U-GBC, comparée aux 4 principales formes qui y sont emboîtées, ressort clairement comme préférable, en particulier lorsqu'on retient dans l'échantillon les observations nulles sur certains trafics - un sujet plutôt négligé à ce jour dans la littérature. Il appert que le coût dépend des caractéristiques techniques telles que la vitesse maximale autorisée sur le segment de ligne et le nombre de croisements de voies, ce qui laisse entendre, comme les caractéristiques techniques couvrent les plus importantes caractéristiques de l'équipement, que les coûts marginaux déduits des ajustements représentent correctement des coûts de court terme ; en outre, la relation entre le trafic et les coûts d'entretien est non-linéaire et varie par type de train. On étudie enfin les implications des diverses spécifications pour la tarification des infrastructures au coût marginal par type de trafic

Shannon's measure of information, path averages and the origins of random utility models in transport itinerary or mode choice analysis

We interpret the often mentioned difference between Logsum and average utility in terms of Shannon's (1948) information measure S, leading to a Path Aggregation THeorem (PATH). It states that, in transport networks where unique measures of the utility of multiple paths are required for demand model formulation purposes and the true path choice model is Multinomial Logit (MNL), constructs based on weighted averages of path characteristics derived from multipath assignments always underestimate the utility of multiple paths, a deficit exactly equal to S (corresponding to minus-one times entropy) if the weights are the path choice probabilities. We study the properties of this S measure of aggregation error, along with those arising from other types of averages of path characteristics, outlining some implications for demand estimation and project appraisal. Notably, the validity of the PATH does not depend on the specific contents of the representative utility functions (RUF) associated to paths, such as their mathematical form or their eventual inclusion of alternative-generic constants (AGC). We show by simulation that averaging modes or sub-modes ― a frequent feature of traffic modeling studies ― can lead to important error in terms of level of traffic and welfare measurement. Concerning the mathematical form of the RUF, we recall that, after the publication of Abraham's 1961 random utility model (RUM) of road path choice deriving the Probit specification based on the Gaussian error distribution (and another specification based on the Rectangular error distribution), French engineers used this seminal approach as justification of road path choice formulae then in current use and assigned the name "Abraham's Law" to a particular standard one, effectively a "Logarithmic Logit" close to the logarithmic RUF carefully specified for Logit mode choice by Warner in 1962. For transit problems, the preference went to a linear RUF, as evidenced in Barbier's casual binomial Probit application to bus and metro, published in 1966, which may have inspired the later generalizations by Domencich and McFadden. In view of many founders' conscientiously crafted nonlinear Logit formulations, and more generally of the repeatedly demonstrated presence of nonlinearity in RUF path and mode specifications since their careful work 50 years ago, we analyze the impact of such nonlinearity on S. This impact is tractable through a comparison of measures S2 and S1 associated with two path choice models differing only in RUF form, as determined by Box-Cox transformations applied to their level-of-service (LOS) variables. We show that, although the difference between measures S2 and S1 may reach a minimum or a maximum with changes in LOS, the solution for such a turning point cannot be established analytically but requires numerical methods: the demonstrable impact on S of nonlinearity, or asymmetry of Logit curve response, is tractable, but only at non trivial computational cost. We point out that the path aggregation issue, whereby aggregation of paths by Logsums differs from aggregation of their characteristics by averages, is not limited to public transit (PT) projects with more or less "common" lines competing in dense urban transit networks (our particular Paris predicament motivating the analysis) but also arises in other modes whenever distinct itineraries or lines compete within a single mode. Concerning dense urban PT networks, we hypothesize that Logsums based on multiple path assignments treating all transit means (about 10 in our problem) as one modal network should, using Ockham's razor, be simpler than the insertion of a layer of choice hierarchies among such urban means based on non nested specifications embodying assumptions on the identity of "higher" and "lower" means, the latter reasserting the multiple path access problems the hierarchies were designed to solve in the first place. Concerning road networks, the proper accounting of multiple path use to avoid Shannon aggregation error points to an abandonment of Wardrop's equilibrium in favor of Logit choice. This completed shift should favor transit when it is the minority mode

Track wear-and-tear cost by traffic class: Functional form, zero output levels and marginal cost pricing recovery on the French rail network

We address the issue of the allocation of railway track maintenance (wear-and-tear) costs to traffic output classes and consider a very general function relating maintenance cost C to a set of technical production characteristics K used to produce traffic output vector T. We neglect other rail cost categories, such as traffic control and track renewal. The data base pertains to over 1500 sections of the French rail infrastructure in 1999, representing about 90% of the total network of 30000 km of lines in regular service. In addition to the maintenance cost C, it provides by track section 15 technical characteristics (both state S and quality Q) and 4 train traffic outputs T. Input prices, assumed to be uniform in space, disappear from the analysis, as in other national cross-sectional cases. With database subsets of approximately 1000 observations, several functional forms are tested: Linear, Log-Log, trans-Log and generalized Box-Cox. All are embedded in an unrestricted extension (U-GBC) of Khaled's seminal restricted generalized Box-Cox (R-GBC) functional specification. The U-GBC architecture, compared with its 4 principal nested variants, turns out to be by far the most appropriate, in particular when some observed zero traffic sample values are included - an issue rather neglected previously in the literature. It appears that several technical characteristics, such as maximum allowed speed and number of switches, are highly significant maintenance cost factors, which gives a hint that derived marginal costs are short term; also, the relation between maintenance costs and traffic is non linear and differs significantly by train category. Implications of different specifications for marginal infrastructure cost charges by traffic type are outlined.rail track wear-and-tear ; cost function ; CES ; trans-Log ; generalized Box-Cox ; zero sample values ; maintenance cost allocation by traffic class ; marginal cost by traffic class ; power axle weight damage laws ; cross-sectional data ; rail line sections ; France ; marginal cost pricing

Optimisation de l'entretien et de la régénération d'une infrastructure : Exploration d'hypothèses

La présente note a pour objet de présenter un cadre formalisé de l'optimisation de la maintenance d'une voie, la maintenance en question comportant d'une part des opérations continues d'entretien courant et d'autre part, à intervalles espacés, des opérations de régénération de l'infrastructure. On supposera à titre principal qu'on est en avenir certain, et dans certains cas on explorera aussi la situation d'incertitude. On en déduira également une expression du coût marginal de maintenance qui comprend comme cas particulier emboîté le résultat routier de Newbey (1988a, 1988b). On proposera enfin des spécifications pour l'économétrie des coûts d'entretien utilisable dans des travaux empiriques en cours avec une base de données sur le réseau ferroviaire français de 1999.optimisation inter-temporelle ; analyse coût-bénéfice ; programmation dynamique ; entretien ; régénération ; entretien d'infrastructure

A comparison of rail liberalisation levels across four European countries

The paper presents the results of a research on railway regulation and liberalisation in Italy, France, Germany and Spain. The analysed fields of regulation are the relationship between the State and the rail companies, network access conditions by operators, slot allocating and pricing schemes and how public service obligations are defined, paid and regulated. The aim of the paper is to give a comparative overview of the rail regulation from a critical point of view, rather than descriptive. The regulatory frameworks are outlined and then assessed according to their implications on the liberalisation level and on the effective market opening. The conclusions are that the actual level of liberalisation is still scarce and only in some cases the opening level is increasing. Market penetration of newcomers is significant only in niche markets. An issue emerging from the work is the opposing attitude of incumbent railways against liberalisation and the role of decision makers in backing this behaviour. The strategies followed to limit the outcomes of the liberalisation process are different across the country sample. However, all the incumbents argue with the self-referential declaration of efficiency, public service obligations and they claim to be under an excessive and unfair foreign competition. These arguments are yet embedded in legislative, organisational and economic settings supporting these positions like the common ownership of network and services, the permanence of dominant positions and favourable financial conditions.railways; liberalisation; regulation; Europe; Italy; France, Germany; Spain

The Social Cost of Air Traffic Delays

The so-called buffer time or buffer delay allows airlines to control for excessive delays by introducing extra time in their schedule in addition to what is technically required. . We study the differences between unregulated markets - where airlines are free to fix their buffer times strategically - and a situation where a social planner would control for time schedules, and in particular the buffer time. To do so, we use a calibrated model of a network of three cities - one of them being a hub - served by a single airline. Welfare losses that follow from delays are relatively small as compared to the potential benefits that would follow from a decrease in ticket prices. The model thus advocates that, at least for the connections that are considered, fares rather than delays should be the focus of institutions aiming at enhancing passengers’ welfare