By JAMES CHEN

Reviewed By GORDON SCOTT 

编写人：JAMES CHEN

审核人：GORDON SCOTT

What Is a Perpetual Bond?

什么是永续债？

A perpetual bond, also known as a "consol bond" or "perp", is a fixed income security with no maturity date. This type of bond is often considered a type of equity, rather than debt. One major drawback to these types of bonds is that they are not redeemable. However, the major benefit of them is that they pay a steady stream of interest payments forever.

永续债，也被称为“统一公债”，是一种没有明确到期日的固定收益证券。这类债券常常被认作权益，而非负债。其中一个主要缺点是不可赎回。但是，最大的益处是永久支付利息。

KEY TAKEAWAYS

关键要点

· Perpetual bonds, also known as perps or consol bonds, are bonds with no maturity date.

· 永续债，也被称为统一公债，是一种没有明确到期日的债券。

· Although perpetual bonds are not redeemable, they pay a steady stream of interest in forever.

· 虽然永续债不可赎回，但会永久支付利息。

· Because of the nature of these bonds, they are often viewed as a type of equity and not a debt.

· 鉴于这种债券的性质，常常被认作权益，而非负债。

Understanding Perpetual Bonds

了解永续债

Perpetual bonds exist within a small niche of the bond market. This is mainly due to the fact that there are very few entities that are safe enough for investors to invest in a bond where the principal will never be repaid.

永续债在债券市场比较小众。主要原因是，只有极少数实体能够让投资者放心地投资连本金都无法偿还的债券。

Some of the notable perpetual bonds in existence are those that were issued by the British Treasury for World War I and the South Sea Bubble of 1720. Some in the U.S. believe the federal government should issue perpetual bonds, which may help it avoid the refinancing costs associated with bond issues that have maturity dates.

现存著名的永续债是英国财政部在第一次世界大战期间发行的战争债券和1720年南海泡沫事件中发行的债券。在美国，有人认为联邦政府应该发行永续债，因为永续债可以避免产生与发行有明确到期日债券相关的再融资成本。

Example of a Perpetual Bond

永续债示例

Since perpetual bond payments are similar to stock dividend payments, as they both offer some sort of return for an indefinite period of time, it is logical that they would be priced the same way.

永续债支付与股票股息支付类似，都会无限期分配某些收益，所以应以相同的方式定价。

The price of a perpetual bond is, therefore, the fixed interest payment, or coupon amount, divided by some constant discount rate, which represents the speed at which money loses value over time (partly due to inflation). The discount rate denominator reduces the real value of the nominally fixed coupon amounts over time, eventually making this value equal zero. As such, perpetual bonds, even though they pay interest forever, can be assigned a finite value, which in turn represents their price.

因此，永续债的价格为定息或息票额除以固定贴现率，贴现率表示货币随时间贬值的速度（部分原因是通货膨胀）。贴现率的分母会随时间降低名义上固定的息票额的实际价值，最终使之等于零。就其本身而论，永续债即使永久支付利息，也可以拥有有限值，反过来表示其价格。

Formula for the Present Value of a Perpetual Bond

永续债现值公式

Present value = D / r

现值=D / r

Where:

其中：

D = periodic coupon payment of the bond

D=债券周期性息票支付额

r = discount rate applied to the bond

r=债券贴现率

For example, if a perpetual bond pays $10,000 per year in perpetuity and the discount rate is assumed to be 4%, the present value would be:

比如，若永续债每年永久性地支付10,000美元，贴现率假设为4%，则现值为：

Present value = $10,000 / 0.04 = $250,000

现值=10,000美元/0.04 =250,000美元

Note that the present value of a perpetual bond is highly sensitive to the discount rate assumed since the payment is known as fact. For example, using the above example with 3%, 4%, 5% and 6% discount rates, the present values are:

请注意，永续债的现值对假设的贴现率高度敏感，因为支付额为已知数额。以上述为例，贴现率分别为3%、4%、5%和6%，则现值为：

Present value (3%) = $10,000 / 0.03 = $333,333

现值（3%）=10,000美元/0.03 =333,333美元

Present value (4%) = $10,000 / 0.04 = $250,000

现值（4%）=10,000美元/0.04 =250,000美元

Present value (5%) = $10,000 / 0.05 = $200,000

现值（5%）=10,000美元/0.05 =200,000美元

Present value (6%) = $10,000 / 0.06 = $166,667

现值（6%）=10,000美元/0.06 =166,667美元