学费增长预测计算器 — 公式

How Endowment Spending Works

Endowments are designed to provide perpetual funding. The spending rate must be low enough that investment returns preserve the real (inflation-adjusted) value of the endowment.

Formula

Annual Spending = Endowment Value x Spending Rate

Sustainable if Spending Rate <= Expected Return - Inflation

Common Practice

  • Most institutions spend 4-5% annually
  • The "Yale Model" suggests 5.25% with a diversified portfolio
  • Spending above the real return rate erodes the endowment over time

    • 计算示例

    A $50M endowment with 5% spending rate, 7% expected return, 3% inflation.

    1. Annual spending: $50M x 0.05 = $2,500,000
    2. Real return: 7% - 3% = 4%
    3. Spending (5%) > Real return (4%): Not sustainable long-term
    4. Net growth: $50M x (7 - 5 - 3)/100 = -$500,000 per year