Aug. 12 2008, useR!2008 in Dortmund, Germany.
ccgarch: An R package for modelling multivariate GARCH
models with conditional correlations
Tomoaki Nakatani
Department of Agricultural Economics
Hokkaido University, Japan
and
Department of Economic Statistics
Stockholm School of Economics, Sweden
1 Multivariate GARCH models
Involve covariance estimation
† Direct:
– VEC representation
– BEKK representation
– GARCH part
† Indirect: through conditional correlations
⁄ Volatility spillovers, asymmetry etc.
⁄ Constant Conditional Correlation (CCC)
⁄ Dynamic Conditional Correlation (DCC)
⁄ Smooth Transition Conditional Correlation (STCC)
– Correlation part
Conditional Correlation GARCH models
2 GARCH part: with/without spillovers
A vector GARCH(1, 1) equation:
ht = a + Aε(2)
t−1 + Bht−1,
εi,t = h1/2
i,t zi,t,
The diagonal specification (no volatility spillovers)
ht =
a10
a20
+
a11
0
0
a22
1,t−1
ε2
2,t−1
ε2
+
b11
0
The extended specification (allowing for volatility spillovers)
ht =
a10
a20
+
a11 a12
a21 a22
1,t−1
ε2
2,t−1
ε2
+
b11
b21
b12
b22
h1,t−1
h2,t−1
[
[
]
]
[
[
][
][
]
]
[
[
zt » ID(0, Pt)
]
][
0
b22
h1,t−1
h2,t−1
][
]
3 Conditional Correlation Part
CCC and ECCC of Bollerslev(1990) and Jeantheau (1998)
Pt = P (constant over time)
DCC of Engle (2002) and Engle and Sheppard (2001)
Pt = (Qt fl IN )−1/2Qt(Qt fl IN )−1/2
Qt = (1 ¡ α ¡ β)Q + αzt−1z
and α, β > 0
α + β < 1
0
t−1 + βQt−1
where Q is a sample covariance matrix of zt.
STCC of Silvennoinen and Ter¨asvirta(2005)
Pt = (1 ¡ Gt)P(1) + GtP(2)
Gt = [1 + expf¡γ(st ¡ c)g]−1, γ > 0
The package
4 Description of the package
Name: ccgarch
Version: 0.1.0 (continuously updated)
Author: Tomoaki Nakatani hnaktom2@gmail.comi
Depends: R 2.6.1 or later
Description: Functions for estimating and simulating the family
of the CC-GARCH models.
Simulating: the first order (E)CCC-GARCH, (E)DCC-GARCH,
(E)STCC-GARCH
Estimating: the first order (E)CCC-GARCH, (E)DCC-GARCH
Availability: Not yet submitted to CRAN. Available upon request.
5 Functions for simulation
CCC-GARCH and Extended CCC-GARCH models
eccc.sim(nobs, a, A, B, R, d.f=Inf,
cut=1000, model)
DCC-GARCH and Extended DCC-GARCH models
dcc.sim(nobs, a, A, B, R, dcc.para,
d.f=Inf, cut=1000, model)
STCC-GARCH and Extended STCC-GARCH models
stcc.sim(nobs, a, A, B, R1, R2, tr.par,
st.par, d.f=Inf, cut=1000, model)