bvar_conj_lambda2hyper: Create prior hyperparameters from lambdas

Description Usage Arguments Details Value Examples

Description

Create prior hyperparameters from lambdas

Usage

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bvar_conj_lambda2hyper(Y_in, Z_in = NULL, constant = TRUE, p = 4,
  lambda = c(0.2, 1, 1, 1, 100, 100), delta = 1, s2_lag = NULL,
  y_bar_type = c("initial", "all"), carriero_hack = FALSE)

Arguments

Y_in

multivariate time series

Z_in

exogeneous variables

constant

logical, default is TRUE, whether the constant should be included

p

number of lags

lambda

vector = (l_1, l_lag, l_sc, l_io, l_const, l_exo), the l_kron is set to 1 automatically for conjugate N-IW prior. Short summary valid for NO sc/io case: sd(const in eq i) = l_const * sigma_i sd(exo in eq i)= l_exo * sigma_i sd(coef for var j lag l in eq i) = l_1*sigma_i/sigma_j/l^l_lag lambdas may be Inf l_io or l_sc equal to NA means no corresponding dummy observations

delta

vector [m x 1] or scalar or "AR1". Are used for prior Phi_1 and in sc/io dummy observations Scalar value is replicated m times. If set to "AR1" then deltas will be estimated as AR(1) coefficients (but not greater than one). Diagonal of Phi_1 is equal to delta. y_bar is multiplied by delta componentwise. By default delta is equal to 1.

s2_lag

number of lags in AR() model used to estimate s2 (equal to p by default) Carriero uses 1 in his matlab code http://cremfi.econ.qmul.ac.uk/efp/info.php

y_bar_type

(either "all" or "initial"). Determines how y_bar for sc and io dummy is calculated. "all": y_bar is mean of y for all observations, "initial": p initial observations Carriero: all, Sim-Zha: initial

carriero_hack

logical, if TRUE sigma^2 will be estimated using biased estimator and supposed error with no square roots in dummy observations will be reproduced FALSE by default

Details

Create prior hyperparameters from lambdas. Lambdas specification is based on Carriero "Bayesian VARs: Specification Choices and Forecast Accuracy" section 3.2.

Value

dummy list containing: Omega, Omega_root S, Phi

Examples

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data(Yraw)
prior <- bvar_conj_lambda2hyper(Yraw, p = 4, lambda = c(0.2, 1, 1, 1, 100, 100))

bdemeshev/bvarr documentation built on May 12, 2019, 3:40 a.m.