The mental discount factor is the rate at which people are currently selling their current value for future results. These rates vary from person to person depending on everyone's willingness to wait. In general, the person who values the present value more than the future has the highest mental discount compared to the person who values it more in the future. Many consumer decisions involve balancing costs and benefits over time. The discounted utility model describes the decision-making problem over time in which different utilities are weighed at different moments in time at the rate of mental time discount.