Model Specification
Model specification is the process of selecting the appropriate mathematical structure and variables for a statistical model. It involves defining the relationships between variables and choosing the correct lags or parameters.
In the case of GARCH, this means deciding the order of the model to best fit the data. A poorly specified model will produce biased or inaccurate forecasts.
This is a critical step in quantitative finance where precision is paramount. Analysts must balance model complexity with the risk of overfitting.
It requires a deep understanding of the underlying data and the market mechanics. Proper specification ensures that the model is theoretically sound and empirically useful.
It is the blueprint for any analytical work.