Questions tagged [garch]
A model for time series in which the conditional variance is time-varying and autocorrelated.
996 questions
0 votes
0 answers
44 views
Hansen SkewT fast numerical approx for E[exp x] and inverse?
I want to fit Hansen $\text{SkewT}(μ, σ, ν, λ)$ with GARCH, fixing $E[e^{r_t}]$ instead of $\mu$. This means at each step the $\mu_t$ will be adjusted. For normal case the adjustment is simple $\mu_t=\...
1 vote
0 answers
89 views
Is GARCH assumption on constant drift wrong in log space?
GARCH assumes constant drift $\mu$ - this imply $E[e^r]$ won't be constant and jump wildly. And it contradicts the reality, for stock prices $E[S_{t}/S_{t-1}]=E[e^r]$ doesn't jump with each time step. ...
1 vote
0 answers
46 views
Autocorrelation between shocks in ARCH(1) model
I'm deep diving into the ARCH model and i had a doubt. While in AR or ARDL model the autocorrelation is a huge problem and the models themselves are shaped for fixing it, I've been reading that, in ...
0 votes
0 answers
32 views
Fitting dynamic EVT POT on standardized residuals of GARCH with rolling window
In implementing the dynamic EVT approach using the Peak Over Threshold (POT) method combined with GARCH(1,1) modeling for forecasting Value-at-Risk (VaR) and Expected Shortfall (ES). When fitting the ...
0 votes
1 answer
68 views
DCC-GARCH for series with unit root
I have a question connected with DCC-GARCH models. Let's have K timeseries, some of them are I(1) series, some - trend-stationary (T) series. For TS time series I can substract trend directly (this ...
1 vote
1 answer
43 views
DCC-GARCH: Valid to have different GARCH models for each series?
Most DCC-GARCH tutorials and guides I found online often use "replicate" in creating their DCC specification, i.e. ...
0 votes
1 answer
93 views
DCC-GARCH: Correct way of choosing between the normal distribution and t-distribution
DCC-GARCH is comprised of two stages: (1) estimating the univariate GARCH and (2) estimating the correlations through DCC. My time series (bond yields) is not normally distributed, as they rejected ...
1 vote
1 answer
65 views
DCC GARCH - Is there any merit in setting omega to zero?
I estimated the univariate GARCH models for each series, and all coefficients are statistically significant. However, upon putting them into one DCC-GARCH model with a DCC(1,1) spec, the individual ...
2 votes
1 answer
69 views
Should the parameters of the DCC-GARCH model be specified simultaneously?
I also learned that in specifying the GARCH model, whether it's a GARCH(1,1) or whatever, that the mean model must be estimated simultaneously and not separately. To put this in to context, sometimes ...
0 votes
1 answer
49 views
DCC-GARCH: Should I get the first difference of both variables even if one is stationary?
I read that one of the preliminary steps before fitting a GARCH model to a series is to test for stationarity. However, DCC-GARCH is modeling the time-varying correlation between two GARCH models. ...
0 votes
1 answer
137 views
Value-at-risk calculation for DCC-GARCH model in rmgarch package
I use rmgarch package for DCC-GARCH model fitting and making forecasts (covariance matrix and MUs) of my portfolio based on it (one-step). So, I use ...
3 votes
0 answers
83 views
What is the actual existence condition for moments in the EGARCH process?
I have encountered different existence conditions for the $m$-th-order unconditional moments of $\epsilon_t$ in the EGARCH process defined as $$\epsilon_t=\sigma_t\eta_t$$ $$\eta_t\sim iid(0,1)$$ $$ \...
0 votes
2 answers
125 views
Combine conditional mean and variance equation to estimate point predictions in ARMA-GARCH model?
An ARMA(p,q)-GARCH(r,s) model specifies the conditional distribution of a time series $x_t$: \begin{aligned} x_t &= \mu_t + u_t, \\ \mu_t &= \varphi_0 + \varphi_1 x_{t-1} + \dots + \varphi_p ...
1 vote
0 answers
118 views
Stationarity conditions for EGARCH
I noticed that there is a difference between the original EGARCH process proposed by Nelson (1991) and the applied versions in standard software. For the original process (I) Nelson already stated ...
1 vote
1 answer
90 views
Similarity between time series using GARCH residuals
I would like to have a reliable measure of similarity between several time series. These represents swap rates of different currencies. I would like to start simple but also make sure I am not missing ...