A 2011 independent study by the National University System Institute for Policy Research analyzed the impact of EPAs on the cost of school construction in California between 1996 and 2008. [119] The study analyzed 551 school construction projects and is, according to some reports, the largest EPA study to date. [120] It appears that the use of AOPs contributed between 13% and 15% to construction costs, which, adjusted for inflation, would represent a cost increase of between $28.90 and $32.49 per square foot. [121] However, the conclusions of this study were strongly disputed by Dr. Dale Belman of Michigan State University, a longtime proponent of the use of PL, whom she repeatedly referred to to earlier research, claiming that the study misjured its findings. In a robust regression analysis, the influence of outliers is reduced, so that more statistical relationships can appear in the results.. . . .