Accounting anomalies distort decision-making at each level of government. The evaluation procedure involves a comparison of the proposed PFI solution with an entirely theoretical-and usually non-fundable-public sector comparator, which may differ significantly from the PFI in terms of output specification. Despite systematic bias (for example, the exclusion of financing costs from the comparison, and the completely unrealistic assumption of zero risk-transfer in the PSC-a contractual structure that would fail to proceed through the Office of Government Commerce Gateway process), these appraisals very often find in favour of the PFI option by just fractions of 1%. PFI is proceeded with on this basis, despite significant uncertainty about the cost estimates of the PSC, the values associated with risk transfer to the private sector and the appropriateness of the discount rate being used in calculating net present values. This process has been widely discredited in the academic literature (eg Gaffney et al 1999). In addition, Jeremy Colman, a former Deputy Comptroller of the National Audit Office, described a tendency for these appraisals to be based on "spurious precision" and "pseudo-scientific mumbo jumbo".