diskonteerimise

Diskonteerimise is a methodological concept in finance and economics describing the process of converting future outcomes into their present value by applying a discount rate. The central idea is time preference: money or benefits available today are regarded as more valuable than the same amount in the future because of factors such as risk, investment opportunities, and uncertainty.

Calculation is typically done by aggregating discounted cash flows. For discrete periods, the present value of a cash flow CF_t received in t years is PV = CF_t / (1 + r)^t, where r is the discount rate. The net present value (NPV) of a project is the sum of successive discounted cash flows. In continuous time, PV = ∫_0^T CF(t) e^{-rt} dt. Rates may be real or nominal, constant or variable over time, and reflect risk, inflation, and opportunity costs. Variants include continuous discounting and alternative approaches such as hyperbolic discounting, which implies diminishing impatience over longer horizons.

Applications include corporate capital budgeting, asset pricing, pension planning, and environmental and public policy analyses where long-term outcomes are weighed, notably via social discount rates.

Critics argue that discounting undervalues long-term or irreversible impacts, particularly for environmental and intergenerational issues. Debates focus on the appropriate rate, whether rates should decline over time, and how uncertainty and distributional effects should be incorporated.