On 19 May 2011, NERA Senior Vice President Dr. Agustin Ros presented a paper he co-authored with Senior Vice President Dr. Jeff D. Makholm and Research Associate Meredith A. Case at a telecommunications and energy workshop hosted by Rutgers University's Center for Research in Regulated Industries. The paper, "Total Factor Productivity and Performance-Based Ratemaking For Electricity and Gas Distribution," uses publicly-available data from the US Federal Energy Commission and other sources to measure total factor productivity (TFP) for 72 US electricity and combination electricity and gas companies for the period 1972-2009. Using TFP is an important element in determining the X-factor in a performance-based ratemaking plan, an alternative to rate-of-return regulation.