Bandingkan kaedah

	Model ARCH Tak Linear (NARCH)	Model EGARCH (Exponential GARCH)
Bidang	Ekonometrik	Ekonometrik
Keluarga	Regression model	Regression model
Tahun asal	1992	1991
Pengasas	Higgins & Bera	Daniel B. Nelson
Jenis	Volatility model	Volatility / conditional variance model
Sumber perintis	Higgins, M. L., & Bera, A. K. (1992). A class of nonlinear ARCH models. International Economic Review, 33(1), 137-158.	Nelson, D. B. (1991). Conditional heteroskedasticity in asset returns: A new approach. Econometrica, 59(2), 347–370.
Alias	NARCH, Nonlinear ARCH, nonlinear conditional heteroscedasticity model, NARCH model	Exponential GARCH, EGARCH, Nelson EGARCH, log-GARCH
Berkaitan	4	6
Ringkasan	The Nonlinear ARCH (NARCH) model, introduced by Higgins and Bera (1992), extends Engle's original ARCH framework by allowing the power transformation of volatility to be estimated from the data rather than fixed at two. This flexibility captures a broader class of volatility dynamics observed in financial and macroeconomic time series.	The Exponential GARCH (EGARCH) model, introduced by Nelson (1991), extends the standard GARCH framework by modelling the logarithm of conditional variance. This ensures variance is always positive without parameter constraints and, crucially, allows negative and positive shocks to have asymmetric effects on volatility — capturing the well-known leverage effect in financial markets.