Ilana Ritov

Who they are

Ritov is Professor of Psychology at the Hebrew University of Jerusalem, a post she has held since 2006 after earlier appointments at Ben-Gurion University and, from 1998, at the Hebrew University. Her university page lists her Ph.D. in psychology from the Hebrew University in 1988, an M.Sc. in mathematics and a B.Sc. in mathematics and English literature. She is affiliated with cognitive science and the School of Education and with the Center for the Study of Rationality, and has been Scientific Director of the I-CORE Center for Empirical Studies of Decision Making and the Law since 2013. She served as President of the European Association for Decision Making from 2009 to 2011.

Key papers

Ritov and Baron's 1992 paper in the Journal of Risk and Uncertainty used scenarios in which change happens unless someone acts. Participants reacted more strongly to bad outcomes caused by action, whether or not the action preserved the status quo, and chose inaction even when inaction still led to change. A matching task that required no action showed no status quo bias. The authors concluded that the status quo bias is at least partly driven by a bias toward omission.

Her earlier paper with Baron, Reluctance to vaccinate: Omission bias and ambiguity (Journal of Behavioral Decision Making, 1990), reports that people are reluctant to vaccinate a hypothetical child when the vaccine itself can cause death, even when that is much less likely than death from the disease it prevents. The abstract calls the reluctance an example of omission bias, a term it credits to Spranca, Minsk and Baron, then in press, and describes it as an overgeneralisation of the distinction between commissions and omissions to a case in which it is irrelevant.

Key ideas

The 1992 paper separates two things that coincide in ordinary life: leaving things alone as a way of keeping the status quo and as a way of not acting. By building scenarios in which they come apart, the authors could ask which one did the work. Their answer, in the abstract, is that omission accounts for at least part of it. Other accounts attribute the bias to loss aversion or to a general preference for the status quo.

---