A recent Danish study shows that consumers are willing to pay extra for products they know are more sustainable.

Despite the fact that eco-labels have been used for a
considerable time, a report by the Danish institute of local
government studies is one of the first empirical studies to show
the relationship between eco-labelling and consumer’s behaviour.
Previous studies have mainly concentrated on the consumers’ ability
of recognising eco-labels. The Danish study analyses the effect of
the Nordic swan on Danish consumers’ decision. It draws the
following conclusions:

• consumers are willing to pay 10-17% more for eco-labeled toilet
  paper and detergents;
• the market share for the Nordic swan labelled products is
  estimated to 6-7%;
• when there are more sustainable alternatives on the market, as
  e.g. reusable dishcloths instead of kitchen paper, consumers will
  not pay extra for eco-labelled products;
• consumers have confidence in the label.

The study shows that eco-labels can play a role in consumers’
behaviour. However, the study would have to be reproduced in other
countries to prove if the result are valid for the EU in general.