It doesn't appear to have been published in a peer-reviewed journal, fwiw, and he carried it out not in his capacity as professor, but in his capacity as owner of the consulting firm Varshney and Associates, which was paid for doing the study. Doesn't make it wrong, but those two factors do make me give it somewhat less weight.

Here's a copy: http://arc.asm.ca.gov/member/5/pdf/CostofRegulationStudyFina...