2.1 The PRA must consider representations that are made to it in accordance with its duty to consult on its general policies and practices and must publish, in such manner as it sees fit, responses to the representations.

2.2 The PRA has considered the responses received to the CP. This chapter sets out the PRA's feedback to those responses, and its final decisions.

2.3 The PRA received ten responses. The responses, and the PRA's feedback on these, have been grouped as follows:

• theory and rationale underpinning the proposals;

• modelling concerns;

• impact and incentives;

• timing and implementation options; and

• other feedback.

Theory and rationale underpinning the proposals

2.4 In CP14/20, the PRA set out its concern that some UK mortgage IRB risk weights were too low, and continued falls would consequently increase prudential risk. The PRA recognised that calculating IRB mortgage risk weights is inherently uncertain and set out a number of observations that had cumulatively influenced the PRA's concern.

2.5 These observations included: