The two most influential models in delay discounting research have been the exponential (E) and hyperbolic (H) models. We develop a new methodology to design binary choice questions such that exponential and hyperbolic discount rates can be purposefully manipulated to make their rate parameters...

The paper surveys over twenty models of delay discounting (also known as temporal discounting, time preference, time discounting), that psychologists and economists have put forward to explain the way people actually trade off time and money. Using little more than the basic algebra of powers...