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9.42 Dedication Mechanics for Coupon Bonds: A Complex Example

Dedication mechanics for coupon bonds requires that we use a reverse-order algorithm, starting with the last (i.e., the three-year) bond first. (Note that the prices of the two-and three-year coupon bonds are indicated in the right-hand margin.) We will then compare the bonds to the Zero-coupon example above.

  • Cash Needs in Third Year: [adjusted for price of bond dedicated to it.]
$4,430,000 ÷ 1.1075 = $4,000,000
Cost: $4,000,000 × 1.00 = $4,000,000 (Par Bond)
(Coupon) Cash flow of three-year bond in earlier years, which will serve to (partially) fund those payments:
Years 1 & 2: $4,000,000 × 1.075 = $430,000
Year 3 (P & I) = $4,430,000
  • Net Year 2 Requirement:
$8,200,000 – $430,000 = $7,770,000
This can be covered with face value of:
$7,770,000 ÷ 1.11 = $7,000,000
Cost: $7,000,000 × 1.009 = $7,063,000 (Premium)
The two-year bond produces interest as well:
Year two (P & I): $7,000,000 × 1.11 = $7,770,000
Year one = $770,000
Combined CFs of Two-and Three- Year bond
Year Three: = $4,430,000
Year Two: $7,770,000 + $4,430,000 = $8,200,000
Year One: $430,000 + $770,000 = $1,200,000
  • Net Year 1 Requirement:
$5,200,000 – $1,200,000 = $4,000,000
Cost: $4,000,000 × 0.90 = $3,636,000 (The zero is discounted)
  • Total Requirement Now:
$3,636,000+ $7,063,000 + $4,000,000 = $14,699,000
Less Zero-Coupon Dedication = $14,703,000 (From pervious example)
Advantage of Coupon Dedication = $4,000

Note:

With more precise pricing than used herein, the two alternatives may exactly equal out.  The choice then becomes a matter of reinvestment risk.

 

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Fixed Income Mathematics Copyright © 2025 by Kenneth Bigel is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.