DescriptionIn decision research, hyperbolic discounting has been used for over 25 years to capture two aspects of impulsivity: 1) dynamic inconsistency--the tendency to initially prefer the long term option (e.g., to save money or exercise more) but then to switch to the short term option--and 2) level of discounting--differentiating those who wait for larger later options from those who prefer proximal options. A model simulation and an empirical experiment show that the hyperbolic discounting function does not accurately predict the relationship between dynamic inconsistency and different levels of discounting. Findings were better fit by an alternative model that incorporates subjective time sensitivity and predicts that extreme impulsiveness will lead not to dynamic inconsistency but rather to consistent preference for proximal rewards.