Abstract
Recent research shows that the Baltic Sea has experienced an ecosystem change and is now in a degraded state. Moreover, it is uncertain whether this deterioration is reversible. We use the referendum approach asking people to vote on a hypothetical abatement program with the purpose of improving the marine water quality of the Baltic Sea where the program is only successful with a certain probability. Our mixed results could have important policy implications as the answer to the question depends very much on how we ask.