Abstract
This paper investigated the extent of the effects of the systematic and surprise changes in budget deficits on the long-term interest rate in South Africa. Use was made of the identified cointegrating vector autoregressive (VAR) techniques whereby cointegrating vectors were identified based on the Fisher effect theory and the expectation hypothesis of the term structure to assess the effect of systematic changes in budget deficit on the long-term interest rate. Moreover, the generalised impulse response functions obtained from the cointegrating VAR were used to assess the effect of the surprise change in budget deficit on the long-term interest rate. The results of the paper showed a positive relationship between the budget deficits and long-term interest rate under different assumptions of price expectations by economic agents.