ACEEE, Jan. 15, 2014, by Martin Kushler, Seth Nowak & Patti Witte.
http://www.aceee.org/research-report/u1401

"Determining the net savings impacts of a program is one of the most prominent and longstanding challenges in the utility energy efficiency field. ACEEE conducted a national review of state approaches to the net savings issue in order to help policymakers, regulators, utilities, and other interested parties better understand this issue and how their peers are addressing it." Free registration required to view full report.