Σύγκριση μεθόδων

	Μοντέλο Fourier ARCH	Μοντέλο ARCH Με Παραμέτρους που Μεταβάλλονται στον Χρόνο (TVP-ARCH)
Πεδίο	Οικονομετρία	Οικονομετρία
Οικογένεια	Regression model	Regression model
Έτος προέλευσης	2010s	1980s–1990s
Δημιουργός	Extends Engle (1982) ARCH framework with Fourier terms following Enders & Lee (2012)	Extension of Engle (1982) ARCH; TVP-ARCH formalization credited to Nicholls & Quinn and subsequent state-space literature
Τύπος	Volatility model with smooth structural change	Conditional heteroscedasticity model with time-varying coefficients
Θεμελιώδης πηγή	Engle, R. F. (1982). Autoregressive conditional heteroscedasticity with estimates of the variance of United Kingdom inflation. Econometrica, 50(4), 987–1007.	Engle, R. F. (1982). Autoregressive conditional heteroscedasticity with estimates of the variance of United Kingdom inflation. Econometrica, 50(4), 987–1007.
Εναλλακτικές ονομασίες	Fourier-ARCH, F-ARCH, ARCH with Fourier terms, Fourier smooth transition ARCH	TVP-ARCH, time-varying ARCH, adaptive ARCH, state-space ARCH
Συναφείς	6	5
Σύνοψη	The Fourier ARCH model extends the classical ARCH framework by incorporating trigonometric (Fourier) terms into the conditional variance equation. This allows the model to capture smooth, gradual shifts in volatility dynamics over time without assuming abrupt structural breaks, making it well-suited for long financial or macroeconomic time series subject to slowly evolving regime changes.	The Time-Varying Parameter ARCH (TVP-ARCH) model extends the classic ARCH framework by allowing both the conditional mean coefficients and the ARCH variance parameters to drift over time according to a random-walk or state-space process. This makes it possible to capture structural shifts in volatility dynamics without imposing a fixed parameter regime.