When Risk Information Changes the Trip: Evidence from a Randomized Panel Combining Discrete Choice and Travel Cost Methods

Coastal bathing delivers large welfare benefits but exposes recreationists to low-probability, high-salience microbial risks that are likely to become more frequent under climate change. Because these risks are largely invisible, behaviour and welfare depend on beliefs and the effectiveness of risk communication. We provide causal evidence on how pathogen-risk information affects preferences and recreation demand using a three-wave panel survey of users of the Gulf of Gdańsk and the Vistula Lagoon (Poland). A stratified national sample identified 3,312 active coastal users in Wave 1 (spring 2024); 2,588 respondents returned in Wave 2 (summer 2024), where they were randomly assigned to receive either minimal information or increasingly detailed pathogen-risk scripts, and then completed a repeated beach-site discrete choice experiment. Approximately one year later (spring 2025), 1,507 users completed a policy-referendum discrete choice experiment on programs combining water-quality improvements, monitoring frequency, and household costs, alongside a repeated travel-cost module capturing multi-day trips and beach outings. Information treatments significantly increased objective and self-assessed knowledge and selectively raised willingness to travel/pay for risk-relevant attributes – especially frequent water-quality monitoring and water-quality improvements – while leaving unrelated attributes largely unchanged. Travel-cost models indicate that information affects trip-taking behaviour, yet the marginal travel-cost sensitivity remains stable, consistent with a demand shift rather than a change in the “price” slope. The results imply that welfare estimates are information-dependent and that credible risk communication can function as a scalable, low-cost complement to traditional coastal health-risk management.