A new analysis has joined the ranks of studies suggesting that companies’ environmental efforts boost their bottom line. The evidence is far from conclusive, however.

Companies considered so-called Meaningful Brands outperformed the stock market by 120 percent, according to the analysis by Havas Media Group. The researchers defined the most meaningful brands as those that systematically improve personal and collective well-being of consumers and are rewarded by stronger brand equity and attachment. The twelve measures of well-being considered include the environment and a “natural” measure. Exactly how much of that good feeling comes from a brand’s environmental performance, Havas didn’t say – though it did note that people in emerging markets place relatively more importance on environmental impacts. Its research also added to the huge body of evidence showing consumers’ distrust of companies (see charts).

But does Havas’s study really measure how well brands improve people’s lives – or just how well their PR machines work? Havas says its Meaningful Brand Index uses consumer perception to compare and track brands’ impacts. That seems a measure of marketing success, not objective performance. The level of customers’ mistrust just gives us one more reason to turn company rankings away from perception, towards reality.

Tamar Wilner is Senior Editor at Environmental Leader PRO.