Estimation of a CIR process with jumps using a closed form approximation likelihood under a strong approximation of order 1

We propose here an approach in order to estimate parameters of the CIR model with jumps in the case where the distribution of jump amplitude is estimated non-parametrically. Since the knowledge of the exact distribution of the jump amplitude is a challenge, in this paper we choose not to fix this law in advance but to estimate it on the basis of the available observations. The method of estimation we propose here is based on the approximation of the closed form of transition density. Since the CIR does not have an explicit solution, it is approximated by the second order Milstein scheme in order to have a more accurate approximation. The method of estimation is then applied on real data, which are the Federal Funds rate and 3 Month T-Bill rate. These two sets of data are used to estimated parameters of the CIR model. We then compare our results to those obtained from Vasicek and Brennon–Swartz models with jumps. Results indicate that there is no clear winner of models competitions. Apparently depending on the nature and structural components of the data, there is a winner. The challenge here is that, there is a trade off between the sample size, the number of jumps and the efficiency of estimates. More data involves the likelihood to have more jumps and thereby less efficient are estimates.