Indeed, a number of reasonable decision measures (e.g., net present value, benefit-cost ratio, internal rate of return, return on investment) depend critically on the chosen discount rate. Why are ...

The discount rate ... value of money. This helps assess whether the future cash flows from a project or investment will be worth more than the capital outlay needed to fund it in the present ...

The discount rate reflects the rate at which individuals or public decision-makers are willing to substitute an effect experienced in the present ... future ones (largely restoration benefits).