Nadeau, Lou, Jeff Cantin, and Richard Wells. "Participation in Voluntary Programs, Corporate Reputation, and Intangible Value: Estimating the Value of Paticipating in the EPA's EnergyStar Program." Working paper, June 2003.

Reviews the impact of participation in the EPA's EnergyStar program on 124 real estate investment trusts (REITs) for the 1999-2001 time period (notes that energy costs can account for 20-40% of REITs' operating costs). Finds that participation in EnergyStar was correlated with higher price/book ratios (p<1%) and higher returns on assets (p<10%). Models include adjustments for size (sq. feet), market concentration, sector representation, and self selection, all of which were statistically significant (p<1%).