Duration is widely used by fixed income managers to proxy the interest rate risk of their assets and liabilities. However, it is well known that the convexity of the price-yield relationship introduces approximation errors that grow with changes in yield. In this article we suggest a new approach, 'discrete duration', which significantly improves upon the accuracy of traditional duration methods and achieves a level of accuracy close to the more complex 'duration-plus-convexity' measure. In particular, discrete duration performs particularly well for long dated and low coupon rate bonds where the estimation error is impressively close to zero.
- interest rate risk
- fixed income