Many decisions involve trade-offs between immediate outcomes and more delayed outcomes.
Subjective discount rates can be inferred from the trade-offs subjects are willing to make. The normative theory of intertemporal choice is discounted utility theory. It prescribes that the same discount rate be applied to all decisions. Actual decisions frequently violate this normative theory. Specifically, discount rates for money are not correlated with those for health, although time preferences are quite consistent within a domain.