Polynomial yield curve models for tilting portfolios

In this paper we will discuss the problem of the desired level of accuracy in model specification. In particular we will look at the effect of various polynomial representations of the yield curve on the tilting of medium to long term bond portfolios. As will be seen, the tilting of these portfolios is very sensitive to the degree of the polynomial used for estimating the yield curve, implying that great care must be taken when forecasting any changes in the structure of the yield curve for such an exercise.