Behavioural insights


EPA Victoria - Sending SMS messages on poor quality water days


The quality of sea-water and beach conditions in Port Phillip Bay is monitored by the Environment Protection Authority (EPA) Victoria. This information is provided to beach users through the EPA website and social media. However, people often put their health at risk by choosing to engage in water-based activities when water quality is poor.


In addition to other studies undertaken by the EPA, another trial the EPA tested in partnership with BehaviourWorks was to send SMS messages alerting beach goers to poor water quality. Between March and April 2016, subscribers were sent SMS alerts on fair and poor water quality days of their nominated beach, advising that conditions may not be suitable for swimming.

The EPA measured whether SMS alerts effectively deterred harmful water based activities by sending a follow up survey to participants. The survey found that 86% of respondents who participate in water based activities and were planning to go to the beach when fair and poor water quality was forecast, changed their decision after receiving the SMS text alert. Furthermore, 95% of respondents indicated they would subscribe to a similar service in the future.

Behavioural insight

Surveys are a common tool employed by behavioural insights that attempt to elicit reporting from respondents on their past actions or provide additional information about why someone behaved in a particular way. While surveys can elicit valuable data, it should be noted that there are limitations of this method, in particular that people often have difficulty reflecting on why they did something, or difficulty recalling exactly how they behaved. Using surveys, it was established that almost all SMS alert recipients found the service useful, and that the vast majority reported that they changed their behaviour because of it.

The EPA and BWA continue to investigate how SMSes work to encourage better choices around water safety. One hypothesis is that sending SMS alerts to beach goers before they arrive speaks to a common bias: the sunk cost fallacy. The sunk cost fallacy describes the situation when people persist with a behaviour that they know to be harmful simply because they have 'already paid for it'. It is common for beach goers to engage in the sunk cost fallacy when they arrive at the beach only to learn that the water quality is poor. Rather than admit that travelling to the beach was a waste of effort, beach goers persist with water based activities they know to be harmful so they can justify the effort of getting there.


By sending SMS alerts to beach goers before they incurred the sunk cost of travelling to the beach, the EPA was better able to encourage responsible decision making.