 These approaches all agree on the broad idea that the correct decision rule weighs probabilities and utilities in linear fashion: multiply then add (see  the entry on expected utility).  A different approach recently pioneered by Buchak (2013, 2014) holds that (in)tolerance for risk throws a non-linear wrench into this equation, however (see also Steele 2007). And taking account of people’s cognitive limitations has long been thought to require further departures from the traditional, linear model (Kahneman and Tversky 1979; Payne, Bettman, and Johnson 1993; Gigerenzer, Todd, and Group 1999; Weirich 2004).