http://plato.stanford.edu/entries/game-theory/#Lab http://www.picoeconomics.com/breakdown.htm http://www.sciencemag.org/cgi/content/full/306/5695/421?ijkey=SB7IYXCdL2or6&#ref20 Graphs are above. The thing is, the hyperbolic discounting curve is 1/(1+kt) and the exponential one is current value = nondelayed value x (1 - discount rate)^delay. By those two curves, value should decrease with respect to time. But the graphs of value above all increase with respect to time. Can anyone clarify these for me? Thanks.