Public Release: 

Would you adhere to a mandatory wildfire evacuation? There are reasons some prefer to stay

A new study provides insight as to why some individuals do not follow evacuation orders when presented with the risk of wildfires

Society for Risk Analysis

Research indicates that climate change has increased the intensity and frequency of wildfires. While many people heed evacuation warnings from officials, there are those who choose to stay and defend their homes, as well as a growing number of individuals who tend to "wait and see." Both a lack of preparedness to defend one's home and a delay in evacuating can increase risk to both public safety and property. How can officials effectively communicate with these varied publics to ensure public safety?

A new study recently published in Risk Analysis: An International Journal uncovers insights into what motivates individuals to evacuate early, wait and see, or stay and defend when faced with a wildfire threat. Much of our understanding of evacuation decisions comes from hurricanes, which usually have a long warning time, can be reasonably forecasted, and for which evacuation is the best choice. In contrast, wildfires are much more unpredictable, making it difficult to predict who needs to evacuate and when. Also, evacuation may not always be the best action, especially when there has been little warning time.

The study, "Should I stay or should I go now? Or should I wait and see? Influences on wildfire evacuation decisions," revealed that those inclined to evacuate believe that evacuation is an effective risk mitigation strategy, and those inclined to stay have a higher tolerance for risk and believe they know how to prepare their property for wildfire.

The researchers surveyed individuals from three fire-prone areas that had experienced fire-driven evacuations in the past three years. The sample included 759 people from Horry County, South Carolina; Chelan County, Washington; and Montgomery County, Texas.

Participants were asked to assess their past evacuation decisions and preparedness activities and were questioned about their beliefs regarding the efficacy of different responses, potential reasons for preparing to evacuate and the importance of various evacuation decision cues, as well as their risk perceptions and risk attitudes.

The researchers used statistical modeling to compare the results of the 'wait and see' and 'stay and defend' respondents to those who leave early. Results indicated that issuing a voluntary evacuation order decreases the odds that an individual will wait and see by 60 percent, and stay and defend by 65 percent. Issuing a mandatory evacuation order decreases the odds by 96 percent and 91 percent, respectively. However, when an individual relies on physical cues such as seeing smoke or flames, this increases the likelihood an individual will wait and see by 158 percent, while an increasing belief that it is possible to safely stay and defend one's home increases the odds of staying and defending by 68 percent.

Respondents were asked to rate whether they are generally prepared to take risks or avoid them altogether (general risk attitude) and were then presented with a series of risky scenarios and asked to rate the likelihood of finding themselves in that situation (safety risk attitude and financial risk attitude). A unit increase in general risk attitude (toward greater risk tolerance) increases the likelihood an individual will stay and defend by 36 percent, while a one unit increase in financial risk attitude decreases the odds of staying and defending by 31 percent.

"Our study begins to provide insight into some of the reasons why wildfire managers see a range of evacuation behavior. Notably we found evidence that different risk attitudes, which have not received much attention in understanding evacuation behavior, are associated with different behaviors," states Sarah McCaffrey, lead author and research social scientist with the USDA Forest Service. "We also found that those who leave early appear to rely solely on official cues to determine when to leave, while the majority (those who either wait and see or stay and defend) rely on both official cues and physical cues. The question this raises is whether individuals understand how to appropriately interpret the physical cues."

As individuals increase their reliance on official cues, they are more likely to evacuate, even if they initially fall into the wait and see or stay and defend groups. However, many individuals are concerned that they will not receive a warning far enough in advance to allow their families to evacuate.

Individuals who wait and see are the largest group and are problematic for authorities who seek to encourage decisive planning and action. This reliance also leads individuals with pre-existing preferences to become less likely to act as they originally intended (i.e. those who initially planned to evacuate deciding to stay and defend).

Since the largest portion of individuals affected by wildfires base their final decision on physical cues, the researchers recommend that communication to this population should focus on how to appropriately assess physical wildfire cues and the challenges of making an accurate assessment. For many, the most appropriate response to wildfire threat will depend upon personal trade-off preferences between safety and property protection.

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About SRA

The Society for Risk Analysis is a multidisciplinary, interdisciplinary, scholarly, international society that provides an open forum for all those interested in risk analysis. SRA was established in 1980 and has published Risk Analysis: An International Journal, the leading scholarly journal in the field, continuously since 1981. For more information, visit http://www.sra.org.

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