Review of technical aspects of the MSI calculation

The UK Regulators and Funders Group commissioned a review of certain technical aspects of the Margin for Sustainability and Investment (MSI) calculation used in the Transparent Approach to Costing (TRAC) process. This was in response to a recommendation arising from a Review of TRAC.

The MSI review was not to look at replacing or removing the MSI calculation from the TRAC return, but considers the assumptions and financial principles of MSI and models the impact of possible changes on the overall MSI calculation.