The economists Steven Levitt and John A. List long pursued without success a search for the base data of the original illumination experiments (the weren't true experiments but some authors labeled them experiments), before finding it in a microfilm at the University of Wisconsin in Milwaukee in 2011. Re-analysing it, they found slight evidence for the Hawthorn effect over the long-run, but in no way as drastic as suggested initially This finding supported the analysis of an article by S R G Jones in 1992 examining the relay experiments. Despite the absence of evidence for the Hawthorne Effect in the original study, List has said that he remains confident that the effect is genuine.