predict | R Documentation |
Forecasts multivariate time series using given model.
## S3 method for class 'varlse'
predict(object, n_ahead, level = 0.05, ...)
## S3 method for class 'vharlse'
predict(object, n_ahead, level = 0.05, ...)
## S3 method for class 'bvarmn'
predict(object, n_ahead, n_iter = 100L, level = 0.05, num_thread = 1, ...)
## S3 method for class 'bvharmn'
predict(object, n_ahead, n_iter = 100L, level = 0.05, num_thread = 1, ...)
## S3 method for class 'bvarflat'
predict(object, n_ahead, n_iter = 100L, level = 0.05, num_thread = 1, ...)
## S3 method for class 'bvarldlt'
predict(
object,
n_ahead,
level = 0.05,
stable = FALSE,
num_thread = 1,
sparse = FALSE,
med = FALSE,
warn = FALSE,
...
)
## S3 method for class 'bvharldlt'
predict(
object,
n_ahead,
level = 0.05,
stable = FALSE,
num_thread = 1,
sparse = FALSE,
med = FALSE,
warn = FALSE,
...
)
## S3 method for class 'bvarsv'
predict(
object,
n_ahead,
level = 0.05,
stable = FALSE,
num_thread = 1,
use_sv = TRUE,
sparse = FALSE,
med = FALSE,
warn = FALSE,
...
)
## S3 method for class 'bvharsv'
predict(
object,
n_ahead,
level = 0.05,
stable = FALSE,
num_thread = 1,
use_sv = TRUE,
sparse = FALSE,
med = FALSE,
warn = FALSE,
...
)
## S3 method for class 'predbvhar'
print(x, digits = max(3L, getOption("digits") - 3L), ...)
is.predbvhar(x)
## S3 method for class 'predbvhar'
knit_print(x, ...)
predbvhar
class with the following components:
object$process
forecast matrix
standard error matrix
lower confidence interval
upper confidence interval
lower CI adjusted (Bonferroni)
upper CI adjusted (Bonferroni)
object$y
See pp35 of Lütkepohl (2007). Consider h-step ahead forecasting (e.g. n + 1, ... n + h).
Let y_{(n)}^T = (y_n^T, ..., y_{n - p + 1}^T, 1)
.
Then one-step ahead (point) forecasting:
\hat{y}_{n + 1}^T = y_{(n)}^T \hat{B}
Recursively, let \hat{y}_{(n + 1)}^T = (\hat{y}_{n + 1}^T, y_n^T, ..., y_{n - p + 2}^T, 1)
.
Then two-step ahead (point) forecasting:
\hat{y}_{n + 2}^T = \hat{y}_{(n + 1)}^T \hat{B}
Similarly, h-step ahead (point) forecasting:
\hat{y}_{n + h}^T = \hat{y}_{(n + h - 1)}^T \hat{B}
How about confident region? Confidence interval at h-period is
y_{k,t}(h) \pm z_(\alpha / 2) \sigma_k (h)
Joint forecast region of 100(1-\alpha)
% can be computed by
\{ (y_{k, 1}, y_{k, h}) \mid y_{k, n}(i) - z_{(\alpha / 2h)} \sigma_n(i) \le y_{n, i} \le y_{k, n}(i) + z_{(\alpha / 2h)} \sigma_k(i), i = 1, \ldots, h \}
See the pp41 of Lütkepohl (2007).
To compute covariance matrix, it needs VMA representation:
Y_{t}(h) = c + \sum_{i = h}^{\infty} W_{i} \epsilon_{t + h - i} = c + \sum_{i = 0}^{\infty} W_{h + i} \epsilon_{t - i}
Then
\Sigma_y(h) = MSE [ y_t(h) ] = \sum_{i = 0}^{h - 1} W_i \Sigma_{\epsilon} W_i^T = \Sigma_y(h - 1) + W_{h - 1} \Sigma_{\epsilon} W_{h - 1}^T
Let T_{HAR}
is VHAR linear transformation matrix.
Since VHAR is the linearly transformed VAR(22),
let y_{(n)}^T = (y_n^T, y_{n - 1}^T, ..., y_{n - 21}^T, 1)
.
Then one-step ahead (point) forecasting:
\hat{y}_{n + 1}^T = y_{(n)}^T T_{HAR} \hat{\Phi}
Recursively, let \hat{y}_{(n + 1)}^T = (\hat{y}_{n + 1}^T, y_n^T, ..., y_{n - 20}^T, 1)
.
Then two-step ahead (point) forecasting:
\hat{y}_{n + 2}^T = \hat{y}_{(n + 1)}^T T_{HAR} \hat{\Phi}
and h-step ahead (point) forecasting:
\hat{y}_{n + h}^T = \hat{y}_{(n + h - 1)}^T T_{HAR} \hat{\Phi}
Point forecasts are computed by posterior mean of the parameters. See Section 3 of Bańbura et al. (2010).
Let \hat{B}
be the posterior MN mean
and let \hat{V}
be the posterior MN precision.
Then predictive posterior for each step
y_{n + 1} \mid \Sigma_e, y \sim N( vec(y_{(n)}^T A), \Sigma_e \otimes (1 + y_{(n)}^T \hat{V}^{-1} y_{(n)}) )
y_{n + 2} \mid \Sigma_e, y \sim N( vec(\hat{y}_{(n + 1)}^T A), \Sigma_e \otimes (1 + \hat{y}_{(n + 1)}^T \hat{V}^{-1} \hat{y}_{(n + 1)}) )
and recursively,
y_{n + h} \mid \Sigma_e, y \sim N( vec(\hat{y}_{(n + h - 1)}^T A), \Sigma_e \otimes (1 + \hat{y}_{(n + h - 1)}^T \hat{V}^{-1} \hat{y}_{(n + h - 1)}) )
Let \hat\Phi
be the posterior MN mean
and let \hat\Psi
be the posterior MN precision.
Then predictive posterior for each step
y_{n + 1} \mid \Sigma_e, y \sim N( vec(y_{(n)}^T \tilde{T}^T \Phi), \Sigma_e \otimes (1 + y_{(n)}^T \tilde{T} \hat\Psi^{-1} \tilde{T} y_{(n)}) )
y_{n + 2} \mid \Sigma_e, y \sim N( vec(y_{(n + 1)}^T \tilde{T}^T \Phi), \Sigma_e \otimes (1 + y_{(n + 1)}^T \tilde{T} \hat\Psi^{-1} \tilde{T} y_{(n + 1)}) )
and recursively,
y_{n + h} \mid \Sigma_e, y \sim N( vec(y_{(n + h - 1)}^T \tilde{T}^T \Phi), \Sigma_e \otimes (1 + y_{(n + h - 1)}^T \tilde{T} \hat\Psi^{-1} \tilde{T} y_{(n + h - 1)}) )
Lütkepohl, H. (2007). New Introduction to Multiple Time Series Analysis. Springer Publishing.
Corsi, F. (2008). A Simple Approximate Long-Memory Model of Realized Volatility. Journal of Financial Econometrics, 7(2), 174-196.
Baek, C. and Park, M. (2021). Sparse vector heterogeneous autoregressive modeling for realized volatility. J. Korean Stat. Soc. 50, 495-510.
Bańbura, M., Giannone, D., & Reichlin, L. (2010). Large Bayesian vector auto regressions. Journal of Applied Econometrics, 25(1).
Gelman, A., Carlin, J. B., Stern, H. S., & Rubin, D. B. (2013). Bayesian data analysis. Chapman and Hall/CRC.
Karlsson, S. (2013). Chapter 15 Forecasting with Bayesian Vector Autoregression. Handbook of Economic Forecasting, 2, 791-897.
Litterman, R. B. (1986). Forecasting with Bayesian Vector Autoregressions: Five Years of Experience. Journal of Business & Economic Statistics, 4(1), 25.
Ghosh, S., Khare, K., & Michailidis, G. (2018). High-Dimensional Posterior Consistency in Bayesian Vector Autoregressive Models. Journal of the American Statistical Association, 114(526).
Korobilis, D. (2013). VAR FORECASTING USING BAYESIAN VARIABLE SELECTION. Journal of Applied Econometrics, 28(2).
Korobilis, D. (2013). VAR FORECASTING USING BAYESIAN VARIABLE SELECTION. Journal of Applied Econometrics, 28(2).
Huber, F., Koop, G., & Onorante, L. (2021). Inducing Sparsity and Shrinkage in Time-Varying Parameter Models. Journal of Business & Economic Statistics, 39(3), 669-683.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.