 The principle of loss aversion (Kahneman &amp; Tversky 1979; Rabin 2000) suggests that the subjective weight that we assign to potential losses is larger than those we assign to potential gains. For example, the endowment effect (Thaler 1980)—the observation that people tend to view the value of a good higher when viewed as a potential loss than when viewed as a potential gain—is supported by neurological evidence for gains and losses being processed by different regions of the brain (Rick 2011). However, even granting the affective differences in how we process losses and gains, those differences do not necessarily translate to a general “negativity bias” (Baumeister, Bratslavsky, &amp; Finkenauer 2001) in choice behavior (Hochman &amp; Yechiam 2011; Yechiam &amp; Hochman 2014). Yechiam and colleagues report experiments in which participants do not exhibit loss aversion in their choices, such as cases in which participants respond to repetitive situations that issue losses and gains and single-case decisions involving small stakes. That said, observations of risk aversion (Allais 1953) and ambiguity aversion (Ellsberg 1961) have led to alternatives to expected utility theory, all of which abandon  A3.  Those alternative approaches include prospect theory  (section 2.4),  regret theory (Bell 1982; Loomes &amp; Sugden 1982), and rank-dependent expected utility (Quiggin 1982).