Modified duration: Difference between revisions

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<span style="color:#4B0082">'''Example'''</span>
<span style="color:#4B0082">'''Example: Modified duration calculations'''</span>


Duration = 5.00 years.  
Duration = 5.00 years.  
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With respect to the EAR:
(i) With respect to the EAR:


MD = 5.00 / 1.0609  
MD = 5.00 / 1.0609  
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With respect to the Semiannual yield:
(ii) With respect to the Semiannual yield:


MD = 5.00 / 1.03  
MD = 5.00 / 1.03  

Revision as of 14:18, 4 December 2015

(MD).

Modified duration is an estimate of the market price sensitivity of an instrument, to small changes in yield.

It is the related proportionate price change of a market instrument or portfolio.


The estimate of change in market price is given by:

Modified duration x Starting Market price x Change in yield


Often - but not always - the relevant yield is defined as the annual effective yield (EAR).

For changes in EAR, modified duration is calculated from Macaulay’s duration as:


MD = Duration / ( 1 + EAR )


For changes in simple nominal annual yields (R), modified duration is calculated as:


MD = Duration / ( 1 + ( R / n ) )

where n = number of compounding periods per year.


Example: Modified duration calculations

Duration = 5.00 years.

Semiannual yield R = 6.00% (so n = 2)

and so EAR = 6.09%.


(i) With respect to the EAR:

MD = 5.00 / 1.0609

= 4.71


(ii) With respect to the Semiannual yield:

MD = 5.00 / 1.03

= 4.85

This shows that there would be a greater proportionate change in price for a 1% change in the Semiannual yield, than for a 1% change in the EAR.


See also