Eco-Labels improve performance?

As marketeers, we assume that a "green" label will be good for sales, especially if it is issued by a reputable credentialing agency. But is it possible that the label actually changes the way people behave?  Here is what a recent academic report found:
People tend to idealize eco-labeled products, but can eco-labeling have consequences for performance? To address this question, 48 university students were asked to undertake a color discrimination task adjacent to a desktop lamp that was either labeled environmentally friendlyor conventional(although they were identical). The light of the lamp labeled environmentally friendlywas rated as more comfortable. Notably, task performance was also better when the lamp was labeled environmentally friendly. Individual differences in environmental concern, but not pro-environmental consumer behavior and social desirability indexes, were related to the magnitude of the eco-label effect on performance. Whilst some previous studies have shown similar placebo-like effects of eco-labels on subjective ratings, this is the first study to show an eco-label effect for artifacts in the built environment on performance, and the first study to relate this effect to environmental concern. Psychological mechanisms that may underpin the eco-label effects are discussed.  (Emphasis added.)
 An interesting finding. We must be cautious about generalizing about the conclusions of one small experiment.

Journal of Environmental Psychology 42 (2015) 123-127 
"An eco-label effect in the built environment: Performance and comfort effects of labeling a light source environmentally friendly"
Authors: Patrik Sorqvist, Andreas Haga, Mattias Holmgren, Andre Hansla