Tommaso Proietti 411
Table 9.2 ML estimation results for bivariate models
of quarterly US log GDP (yt) and the consumer price
inflation rate (pt), 1950:1–2006:4
Bivariate Great Moderation
Parameter Std. error Parameter Std. error
ytequation
ση^2 0.33 0.14
ση^2 a 0.58 0.27
ση^2 b 0.13 0.05
σκ^2 0.38 0.15
σκ^2 a 0.47 0.24
σκ^2 b 0.06 0.04
φ 1 1.47 0.06 1.55 0.06
φ 2 −0.54 0.10 −0.60 0.09
ptequation
σp^2 ε 0.11 0.03 0.12 0.03
στη^2 0.05 0.02 0.05 0.02
θψ 0 0.12 0.05 0.12 0.06
θψ 1 −0.10 0.05 −0.10 0.06
Wald tests of restrictionθψ( 1 )= 0
2.00 1.68
loglik −447.79 −415.53
ergodic Markov chain whose invariant distribution is the target density (see Chib,
2001, and the references therein).
This is achieved by the following iterative scheme. Specify an initial value
α(^1 ),(^1 ). Fori=1, 2,...,M:
- Generateα(i)∼f(α|(i−^1 ),y)using the simulation smoother (see Appendix C,
section 9.7.4) - Generate(i)∼f((i)|α(i),y). This block is divided into smaller components,
whose full conditional distribution is available for sampling. In particular:
(a) Generate(φ( 1 i),φ 2 (i))′from the full conditional(φ 1 ,φ 2 )′|ψ,σκ^2 (i−^1 )(this distri-
bution is conditionally independent ofy, givenψ). Assuming a Gaussian
prior distribution, N(mφ 0 ,φ 0 ),(φ 1 ,φ 2 )′|ψ,σκ^2 (i−^1 )∼N(mφ 1 ,φ 1 )where,
denotingχt− 1 =(ψt(−i− 11 ),ψt(i−− 21 ))′,
φ 1 =
⎛
⎝φ− 01 +^1
σκ^2 (i−^1 )
∑
t
χt− 1 χ′t− 1
⎞
⎠
− 1
,
mφ 1 =φ 1
⎛
⎝φ− 01 mφ 0 +^1
σκ^2 (i−^1 )
∑
t
χt− 1 ψt
⎞
⎠.