To determine a single and ‘precise’ value for each of the input parameters is somewhat problematic.
Careful consideration of the input parameters will help establish a reasonable range for the ต้นทุนเงินทุน within the CAPM approach.
The choice of a rate of return within this range is a matter of regulatory judgement.
This judgement may be informed by the results of alternative models for assessing the ต้นทุนเงินทุน assessment of risks specific to the utility, and evidence of market expectations.