Asymptotic properties and drift parameter estimations of the ergodic double Heston model based on continuous-time observations
Mohamed Ben Alaya, Houssem Dahbi, Hamdi Fathallah
TL;DR
This work analyzes a three-factor double Heston diffusion in an affine diffusion framework to address both probabilistic and statistical properties. It first classifies the long-run behavior of the model into subcritical, critical, and supercritical regimes, establishing a unique stationary distribution and exponential ergodicity under suitable drift conditions. It then develops continuous-time MLE and CLSE methods for the drift parameters, proving strong consistency and asymptotic normality in the ergodic (subcritical) setting, with explicit limit covariance structures derived from stationary behavior. Numerical simulations corroborate the theoretical results, showing faster convergence for MLE relative to CLSE and illustrating the practical applicability of the inference procedures for calibrated stochastic-volatility models.
Abstract
The double Heston model is one of the most popular option pricing models in financial theory. It is applied to several issues such that risk management and volatility surface calibration. This paper deals with the problem of global parameter estimations in this model. Our main stochastic results are about the stationarity and the ergodicity of the double Heston process. The statistical part of this paper is about the maximum likelihood and the conditional least squares estimations based on continuous-time observations; then for each estimation method, we study the asymptotic properties of the resulted estimators in the ergodic case.
