ABSTRACT
Standard economics assumes that people are consistent when they plan their decisions over time. In the standard economic model, People’s choices will be stable over time. Deviations from the rationality come when time preferences shift, when people are impatient in the short run but patient in the long run. If someone has a high discount rate and so values future outcomes less strongly then they can be described as rational if their impatience is stable over time. In capturing the limits to people’s ability to plan for the future, some behavioural economists start with adjustments to orthodox models of inter-temporal planning. N. J. Mulcahy and Tversky Call find that animals plan over time, for example bonobos and orangutans select, transport and save tools to use one hour later and 14 hours later and they infer that planning skills may have evolved in earlier species.
