This method calculates an average that gives more weight to values covering longer periods. For example, if a portfolio’s return is 10% over one year and 5% over the following three years, the average return isn’t simply (10% + 5%) / 2 = 7.5%. Instead, the three-year period receives proportionally more weight, resulting in a lower weighted average that more accurately reflects performance over the entire four-year span. This approach often involves geometric linking of returns to account for compounding.
Its significance lies in providing a truer representation of performance or value over time, especially in scenarios with varying durations. This contrasts with a simple average, which can be misleading when periods are unequal. Accurately assessing investment portfolio returns, internal rates of return, and even average concentrations of pollutants in environmental science benefits from this weighted approach. Its historical context traces back to the need for fairer and more representative performance evaluation in finance and related fields.