A principal questão no recurso a contratos de concessão para executar o programa de investimento público é a partilha de riscos entre o Concedente (parceiro público) e o concessionário (parceiro privado) não só no momento da adjudicação mas também ao longo da duração do contrato de concessão.
Irwin define "garantia" como um acordo em que o Estado-Concedente garante um determinado resultado, seja um certo nivel de receita ou de custos, etc, de maneira que o Estado-Concedente (isto é o contribuinte) acaba por assume alguns dos riscos de um projecto.
A partilha ou afectação de riscos entre os parceiros pode considerar-se optimizada no momento da adjudicação se resultou de um concurso público internacional bem conduzido, com bom Value for Money para o Concedente e um contrato equilibrado para todas as partes. A partir desse momento, o Concedente vai perdendo poder negocial devido às assimetrias de informação e de capacidades técnicas que favorecem os concessionários nas sucessivas renegociações. Negociações essas que são inevitáveis dada a longa duração e complexidade dos contratos.
Em última instância, o Concedente retém a responsabilidade global pelos projectos, pois os serviços públicos não podem fechar, e os operadores não estão sujeitos à normal disciplina do mercado.
Diz Irwin (pg 3):
The difficulty of knowing how best to allocate risks is compounded by other problems.
First, politics can encourage governments to bear more risk than is in the public interest. Governments are buffeted on all sides by proposals for subsidies, but unless the beneficiaries are widely regarded as deserving, the most transparent of such proposals tend to fail.
Successful proposals tend to have opaque costs and to come with a rationale explaining how they are good for the country and don’t merely redistribute value. Proposals for guarantees can meet these criteria, especially when the government’s accounting and budgeting fail to recognize their costs. They come with plausible rationales about risk sharing, and taxpayers are unlikely to understand the costs.
Second, government decisions would be difficult even in the absence of political pressures. Psychological research shows that people struggle to make accurate judgments about risks and then fail to make the best use of even their imperfect judgments. Most people, for example, are overconfident in their judgments and therefore think the world is more predictable than it is. Government decision makers may fall into the same trap, underestimating the risks to which they are exposing the public when they issue guarantees. They may also make decisions about guarantees that are irrational given their judgments. Research shows that people can switch from being risk averse to being risk seeking just because the framing of a choice changes. They can also be irrationally risk averse when they consider risks one by one, instead of thinking of their total portfolio of assets and liabilities. Sensitized to the risks created by government guarantees by stories such as those of Korea and 19thcentury Argentina, governments may be needlessly timid about taking risks that are small in the scheme of things.
In sum, governments can easily make poor decisions about guarantees.
There is no simple solution to this problem, but good decisions are more
likely if three conditions are met:
1. The government’s advisers and decision makers have a framework for
judging when a guarantee is likely to be justified.
2. The government’s advisers know how to estimate the cost of a guarantee.
3. The government’s decision makers follow rules that encourage careful
consideration of a guarantee’s costs and benefits.
Helping governments fulfill these three conditions is the aim of
this book."
Fonte: Banco Mundial, obter .pdf aqui