In this paper, we consider possibly misspecified stochastic differential equation models driven by L\'{e}vy processes. Regardless of whether the driving noise is Gaussian or not, Gaussian quasi-likelihood estimator can estimate unknown parameters in the drift and scale coefficients. However, in the misspecified case, the asymptotic distribution of the estimator varies by the correction of the misspecification bias, and consistent estimators for the asymptotic variance proposed in the correctly specified case may lose theoretical validity. As one of its solutions, we propose a bootstrap method for approximating the asymptotic distribution. We show that our bootstrap method theoretically works in both correctly specified case and misspecified case without assuming the precise distribution of the driving noise.
翻译:在本文中,我们考虑L\'{{{e}vy 过程驱动的随机差异方程模型可能定义错误。 无论驱动器的噪音是高斯还是不是高斯,高斯准相似度估计器可以估计漂移和比例系数中的未知参数。然而,在错误描述的情况下,估计器的无症状分布因误差偏差的纠正而不同,在正确指定的案例中,对无症状差异的一致估计器可能会失去理论有效性。作为解决办法之一,我们提出了一种约合于无症状分布的靴式方法。我们表明,我们的靴式方法理论上在正确的特定情况下和错误描述的情况下都起作用,而没有假定驾驶器的准确分布。