This section examines the two central drivers behind the use of PPP in NI, outlined in section 2: namely, the claim that private finance can deliver extra resources for public investment; and that it can enhance the macro-economic value of NI. The argument is presented that these rationales are without merit: the only credible rationale for the use of PPP is that it is capable of delivering projects and services with greater efficiency or "value for money", than the alternatives. The final part of this section provides a review of the evaluative literature on the issue of value for money.