Sobrecostes e infrabeneficios. las previsiones en proyectos de transporte.

Ultimamente he estado leyendo varios articulos de Flyvbjerg, uno de los principales autores actuales en temas de analisis de proyectos de transporte. Aunque ya le cité hablando del Madrid-Barcelona, tiene citas muy interesantes que aplican, no solo a proyectos de transporte sino en general a cualquier inversión que requiera de un analisis Costo-Beneficio. Este es un articulo largo y pesado en citas de este articulo (Survival of the unfittest: why the worst infrastructure gets built—and what we can do about it. Oxford Review of Economic Policy, Volume 25, Number 3, 2009, pp.344–367 Bent Flyvbjerg) que resume gran parte del estado del arte y de los problemas de las previsiones en proyectos.

Por ejemplo, hablando sobre los origenes de los sobrecostes dice:

“In the grip of the planning fallacy, managers make decisions based on delusional optimism rather than on a rational weighting of gains, losses, and probabilities. They overestimate benefits and underestimate costs. They involuntarily spin scenarios of success and overlook the potential for mistakes and miscalculations. As a result, managers pursue initiatives that are unlikely to come in on budget or on time, or to deliver the expected returns.”

Incluso se atreve a dar una formula que asegura la financiación del proyecto.

underestimated costs + overestimated benefits = funding

Using this formula, and thus ‘showing the project at its best’ as one interviewee said above, results in an inverted Darwinism, i.e the survival of the unfittest. It is not the best projects that get implemented, but the projects that look best on paper. And the projects that look best on paper are the projects with the largest cost underestimates and benefit.

Esta dinamica genera graves problemas, puesto que los proyectos que se comparan no son reales sino la versión idealizada y sobredimensionada de los mismos teniendo todos los agentes que participan en el proceso los incentivos maximos para desviarse hacia el caso mas favorable de su proyecto. Asi parece que todos los proyectos propuestos son inversiones ruinosas pero realmente existen buenos proyectos, con unos resultados menos susceptibles a sobreestimaciones y que no se consideran en ningún analisis porque aparentemente son menos rentables que los proyectos estrella.

Eso hace ademas que:

Therefore the projects that have been made to look best on paper in this manner become the worst, or unfittest, projects in reality, in the sense that they are the very projects that will encounter most problems during construction and operations in terms of the largest cost overruns, benefit shortfalls, and risks of non-viability. They have been designed like that, as disasters waiting to happen.

Una de las causas que cita se debe a la propia competeción entre agencias y/o proyectos para conseguir financiación, que fuerza a mejorar la imagen del propio proyecto lo maximo posible.

Political-economic explanations see project planners and promoters as deliberately and strategically overestimating benefits and underestimating costs when forecasting the outcomes of projects. They do this in order to increase the likelihood that it is their projects, and not the competition’s, that gain approval and funding. […] Competition between projects and authorities creates political and organizational pressures that in turn create an incentive structure that makes it rational for project promoters to emphasize benefits and de-emphasize costs and risks. A project that looks highly beneficial on paper is more likely to get funded than one that does not.

Afortunadamente, tambien recomienda metodologias para mejorar las previsiones  en los analisis de coste-beneficio de los proyectos, utilizando Pronosticos por clase de referencia (el articulo de wikipedia pone ejemplos de aplicación en transporte) como metodologia para eliminar el sesgo optimista de los analistas.

Reference class forecasting requires the following three steps for the individual project:
(i)    identification of a relevant reference class of past projects. The class must be broad enough to be statistically meaningful but narrow enough to be truly comparable with the specific project;
(ii)    establishing a probability distribution for the selected reference class. This requires access to credible, empirical data for a sufficient number of projects within the reference class to make statistically meaningful conclusions; and
(iii)    comparing the specific project with the reference class distribution, in order to establish the most likely outcome for the specific project.

Esta metodologia ataca a una de las fuentes fundamentales de las desviaciones, permitendo que la experiencia previa de otros proyectos mejore los resultados, algo que hasta ahora no esta ocurriendo. Ademas hay que modificar los incentivos de los gestores publicos para fomentar la realización de proyectos realmente utiles. Para eso proponen las siguientes recomendaciones para agentes publicos.

  • National-level government should not offer discretionary grants to local agencies for the sole purpose of building a specific type of project (a.k.a. ‘categorical grants’). Such grants create perverse incentives. Instead, national government should simply offer ‘block grants’ to local governments, and let local political officials spend the funds however they choose to, but make sure that every dollar they spend on one type of project reduces their ability to fund another.
  • Cost–benefit analysis and other types of ex ante appraisal should be shifted from promoters to more neutral ground, for instance with the Treasury, in order to reduce risks of agency problems.
  • Forecasts and business cases should be made subject to independent peer review. Where projects involve large amounts of government funds, such review may be carried out by national or state auditing offices, such as the General Accounting Office in the USA or the National Audit Office in the UK, who have the independence and expertise to  produce such reviews.
  • Forecasts should be benchmarked against comparable forecasts, for instance using  reference class forecasting as described in the previous section. For publicly funded projects, forecasts, peer reviews, and benchmarkings should be made available for public scrutiny, including by the media, as they are produced,  including all relevant documentation.
  • Public hearings, citizen juries, and the like should be organized to allow stakeholders and civil society to voice criticism and support of forecasts. Knowledge generated in    this way should be integrated in project management and decision-making.
  • Scientific and professional conferences should be organized where forecasters would present and defend their forecasts in the face of colleagues’ scrutiny and criticism. Projects with inflated benefit–cost ratios should be reconsidered and stopped if recalculated costs and benefits do not warrant implementation.
  • Projects with realistic estimates of benefits and costs should be rewarded. Professional and occasionally even criminal penalties should be enforced for managers and forecasters who consistently and foreseeably produce deceptive forecasts (Garett and Wachs, 1996).

Para los casos de colaboraciones publico privadas las recomendaciones son parecidas:

  • The decision to go ahead with a major infrastructure project should, where at all possible, be made contingent on the willingness of private financiers to participate without a sovereign guarantee for at least one-third of the total capital needs.
  • This should be required whether projects pass the market test or not—that is, whether projects are subsidized or not or provided for social justice reasons or not. Private lenders, shareholders, and stock-market analysts would produce their own forecasts or conduct due diligence for existing ones. If they were wrong about the forecasts, they and their organizations would be hurt. The result would be added pressure to produce realistic forecasts and reduced risk to the taxpayer.
  • Forecasters and their organizations must share financial responsibility for covering cost overruns and benefit shortfalls resulting from misrepresentation and bias in forecasting. The participation of risk capital would not mean that government reduces control of major infrastructure projects. On the contrary, it means that government can more effectively play the role it should be playing, namely as the ordinary citizen’s guarantor for ensuring concerns about safety, environment, risk, and a proper use of public funds.

De cara a mejorar tambien la calidad de los proyectos realizados por pequeñas administraciones y agencias publicas, que apenas realizan grandes proyectos y no alcanzan una masa critica de grandes proyectos como para acumular experiencia, Flyvbjerg realiza una recomendación muy sensata, una oficina de contratación central como apoyo para mejorar esa contratación publica.

A possible way to bring more symmetry into the client–contractor relationship would be for government to establish a central contract-writing unit at the state or national level, which would be in charge of negotiating, on behalf of local and other branches of government, the types of major contracts they do too infrequently to gain real experience. This would concentrate a larger number of contracts in one place, allowing experience—and the negotiating power that comes with it—to accumulate.

La participación de agentes externos para financiar los proyectos, basicamente bancos, fondos soberanos, de pensiones etc.. es recomendable en cuanto obliga a realizar mejores previsiones y a que el inversor analice la inversión con otro enfoque, aunque la gestión siga perteneciendo al ente publico.

Banks typically bring in their own advisers to do independent forecasts, due diligence, and risk assessments, which is an important step in the right direction. The false assumption that one forecast or one business case (which is also a forecast) may contain the truth about a project is problematized. Instead project managers and promoters are getting used to the healthy fact that different stakeholders have different
forecasts and that forecasts are not only products of objective science and engineering but of negotiation. Why is this more healthy? Because it is more truthful about our ability to predict the future and about the risks involved.

Pese a que la situación descrita no es precisamente optima, los mecanismos ya existentes en Europa (los paises mas avanzados son Holanda, Suiza, UK y Dinamarca) tienen un efecto importante y la experiencia acumulada en todos los niveles ha mejorado la calidad de las previsiones, al menos si la comparamos con el resto del mundo.

A recent study documented that the average cost overrun on rail projects—measured in real terms from the decision date to completion—was 64.6 per cent in emerging economies against 40.8 per cent in North America and 34.2 per cent in Europe (Flyvbjerg et al., 2002, p. 285)

Las medidas que se comentan en este articulo van en la misma linea que las que inclui en este post, tambien cuando hablé del MAD-BCN, del proyecto de Sttutgart-21 o de la metodologia de la NAO del UK. Realmente hay mucha literatura cientifica tanto desde puntos de vista economicos como tecnicos sobre los resultados de los proyectos realizados, muy buenas estimaciones de demanda y metodologias de analisis, costo-beneficio y otras, pero la conexión de ese conocimiento con la implementación real es muy limitada y el enfoque, sobre todo en España es muy determinista, aunque hay gente que ya habla de incluir previsiones estocasticas en los proyectos, algo que apoyo fehacientemente.

Como cierre una cita incluida en el articulo que es especialmente dura, pero necesaria dado el estado de las cosas en el mundo.

‘Anyone who causes harm by forecasting should be treated as either a fool or a liar. Some forecasters cause more damage to society than criminals’ (The Black Swan, Taleb, 2007, p. 163).

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