After hurricanes Harvey and Irma, the National Science Foundation (NSF) funded research to investigate the broad impacts of these disasters. A year later, some of the researchers funded by awards from the agency’s Social, Behavioral, and Economic Sciences Directorate are reporting results produced to date. This is the fourth article in the series. Roxane Cohen Silver, professor of psychological science, medicine, and public health at the University of California, Irvine studies the details of why people chose to evacuate or stay put as Hurricane Irma approached.