Whose Growth rate to use in PEG calculations?

Whose Growth rate?

In computing PEG ratios, we are often faced with the question of whose growth rate we will use in estimating the PEG ratios.

If the number of firms in the sample is small, you could estimate expected growth for each firm yourself.

If the number of firms increases, you will have no choice but to use analyst estimates of expected growth for the firms. Will this expose your analyses to all of the biases in these estimates? Not necessarily. If the bias is uniform – for instance, analysts over estimate growth for all of the firms in the sector – you will still be able to make comparisons of PEG ratios across firms and draw reasonable conclusions.

http://zonecours.hec.ca/documents/A2009-1-1877347.ch18-earning-multiple(1).pdf