Unified discrete-time and continuous-time models and statistical inferences for merged low-frequency and high-frequency financial data
融合低频与高频金融数据的统一离散时间和连续时间模型
This paper introduces a unified model, which can accommodate both continuous-time Itô processes used to model high-frequency stock prices and GARCH processes employed to model low-frequency stock prices, by embedding a discrete-time GARCH volatility in its continuous-time instantaneous volatility. This model is called a unified GARCH-Itô model. We adopt realized volatility estimators based on high-frequency financial data and the quasi-likelihood function for the…