We devise a “nudging” natural field experiment to test the impact of a simple form of advertising on environmentally responsible products with/without the increase of the responsible product price. We find that the simple use of a small shelf poster explaining the importance of buying a green product (with/without a concurring price increase) generates significant changes in market shares for some of the product classes for both food and non-food products. Part of the effect is generated by the reduced price elasticity of consumers to the poster-plus-price-increase treatment
