The Nelson-Siegel model is widely used in practice for fitting the term structure of interest rates. Due to the ease in linearizing the model, a grid search or an OLS approach using a fixed shape parameter are popular estimation procedures. The estimated parameters, however, have been reported...

The Nelson-Siegel and the Svensson models are widely used in practice for fitting the term structure of interest rates. However, due to their highly non-linear nature and the potential danger of multicollinearity, numerical difficulties in estimating these models hamper their implementation. In...