NEWS
sstvars 1.2.4 (2026-05-29)
- Implemented the branch-and-bound method of Gripenberg (1996) for bounding the JSR in C++ for speed improvements in the function "bound_JSR".
The old R implementation is still available in the function "bound_JSR_G".
- Added the function get_penalized_IC to compute the information criteria based on the penalized log-likelihood function for models estimated via penalized ML.
- Added the functionality to plot so-called "shotgun plots" for the GIRFs. To plot a shotgun plot, use the argument "type=shotgun" the plot method for GIRF objects.
- Updated the reference Virolainen (2025) to Virolainen (in press) (identification by non-Gaussianity in structural smooth transition vector autoregressive models)
- Updated the discussion on identitication by non-Gaussianity in the vignette to match the latest version of the paper introducing the method (Virolainen, in press).
- Minor updates to the documentation, including typo fixes etc.
sstvars 1.2.3 (2026-01-26)
- Improved the robustness of the function drawing independent skewed t random variables to extreme values.
- Corrected some interpretations related to the counterfactuals in the vignette and function documentations.
- Minor updates to the documentation.
sstvars 1.2.2 (2025-09-15)
- The returned object from reorder_B_columns, swap_B_signs, and swap_parametrization now includes estimation results from all estimation rounds identically to
the original model (i.e., these results do now not have the impact matrices nor the parametrization changed).
- Updated the vignette to match the current version of Virolainen (2025).
- Updated the data file usacpu to match the current version of Virolainen (2025).
- Updated the reference to Lanne and Virolainen (2025).
sstvars 1.2.1 (2025-06-19)
- Fixed the labels for variables in GIRFs etc when they were calculated using a model either not containing any data or containing data without variable names.
- Removed the fixed "lwd" setting from the plot method for historical decompositions. The line thickness can now be adjust with the dot parameters.
- If a matrix is provided as the argument "init_vals" in GIRF or GFEVD, it is now automatically converted to the appropriate array.
- Fixed a bug in the counterfactual functions that caused an error when only a warning (about the small effect of the shock the policy variable) should have been thrown.
- Improved the data documentation.
sstvars 1.2.0 (2025-04-30)
- MAJOR: Added three new functions for conducting counterfactual analysis, policy counterfactuals in particular. The new functions are
cfact_hist (for historical counterfactuals), cfact_fore (for counterfactual forecast scenarios), and cfact_girf (for counterfactual
generalized impulse response functions). See the vignette for details on the implemented methods.
- MAJOR: Added the new function hist_decomp that allows to compute historical decompositions for TVAR and STVAR models. See the vignette for details.
- It is not possible in the genetic algorithm to only allow for estimates that allocate a specified amount of observations to each regime
(see ??GAfit and the arguments bound_by_weights and min_obs_coef_ga).
- Bug fix: There was an issue with the Phase 1 estimation of the three-phase estimation when weight_function = "exogenous" (NLS estimates were not calculated
correctly). This is now fixed.
- Previously the documentation of fitSTVAR incorrectly stated that two-phase estimation method is the default all but TVAR models, although it is the default for
only relative_dens models. The documentation has been updated to clarify this.
- Fixed some typos and similar type of editing issues from Section 2.1 of the vignette.
- Adjusted the argument min_obs_coef to work slightly more accurately. This might have some effect on the obtained estimates.
- Removed the internally used argument girf_pars from simulate.stvar.
sstvars 1.1.6 (2025-04-08)
- Now also for models estimated via penalized ML, the values of the information criteria are calculated using the log-likelihood without the penalization term.
- Added the argument "h" to functions fitSTVAR and fitSSTVAR, which allows to specify the difference in finite difference approximation of the gradient used in
numerical optimization.
- In the function profile_logliks, added the missing subscript to elements of the impact matrix B_m to indicate the corresponding regime.
sstvars 1.1.5 (2025-04-01)
- Updated the vignette to align with latest version of the working paper \url{https://arxiv.org/abs/2404.19707} of Virolainen,
establishing identification by non-Gaussianity for TVAR and STVAR models.
- In the documentation, simplified the notation of the intercept parameters from \phi_{m,0} to \phi_{m}.
sstvars 1.1.4 (2025-02-27)
- Now also for Gaussian models, the functions GIRF and GFEVD use simulation procedure to draw initial values from a specific regime when init_regime is used
and not use_data_shocks. This ensures that the transition weights are high for the initial regime at impact, while with stationary distribution that was not checked.
- In simulate.stvar the default for Gaussian models is now also use simulation procedure to draw initial values from a specific regime, ensuring that the transition weights
are high for the initial regime based on the initial values. The newly argument use_stat_for_Gaus can be set to TRUE to use stationary distribution instead (as was the
old functionality).
- Added the possibility to use more sparse grid in LS/NLS estimation by adding the argument sparse_grid to fitSTVAR.
- Fixed a bug causing the argument min_obs_coef in fitSTVAR to be ignored in the LS/NLS estimation step.
- Fixed a bug in plot.girf in which the y-axis was not wide enough when the point estimate is outside the "confidence bounds".
- The object returned by fitSTVAR now includes also the seeds used in the estimation (if specified).
- Updated the datafile usacpu to include observations until the end of 2024.
- Updated the references.
- Updates to the documentation.
sstvars 1.1.3 (2025-01-30)
- Fixed a bug that prevented printing models that impose restrictions on the AR parameters.
- Now fitSTVAR normalizes the first row of the impact matrix B_1 to be positive and in a decreasing order also for skewed t models.
- Now swap_B_signs also swaps the signs of the appropriate skewness parameter values for skewed t models, so that the resulting model
is observationally equivalent to the original model.
- Increased the default maxit from 1000 to 2000 in fitSTVAR.
sstvars 1.1.2 (2025-01-08)
- A new feature in GFEVD: initval_type = "data" and use_data_shocks = TRUE now allows to filter the histories based on the dominance of
a specific regime.
- A new feature in GIRF: use_data_shocks, which allows to estimate the GIRF using the length p histories in the data, using the shocks recovered
from the fitted model, with the possibility to filter the histories based on the dominance of a specific regime as well as on the sign and
size of the shocks.
- GFEVDs are now calculated as the average over the GFEVDs based on the different initial values (previously calculated based on the average of the GIRFs
based on the different initial values).
- Fixed the function stvar_to_sstvars110.
- Fixed a bug that caused GFEVD with data shocks to result in error when using model estimate with package versions <1.1.0.
- Various small adjustments to printouts, documentation, etc.
sstvars 1.1.1 (2024-12-07)
- Now also the NLS step in the three-phase estimation estimation checks that there are enough observations from each regime
(previously only LS estimation checked this).
- Added the argument min_obs_coef to fitSTVAR to let the user to control the smallest accepted number of observations from each regime in
the LS/NLS step of the three-phase estimation. Also increased its default value.
- Now alt_stvar, iterate_more, and filter_estimates retain LS_estimates if the original model contains them.
- Now summary printout of class sstvar objects tells if the log-likelihood function is penalized.
- Fixed CRAN check issues.
sstvars 1.1.0 (2024-11-29)
- MAJOR: Implemented independent skewed t distribution as a new conditional distribution.
- MAJOR: Implemented a three phase estimation for TVAR models to enhance computational efficiency.
- MAJOR: Implemented a possibility to maximize penalized log-likelihood function that penalizes from unstable and close-to-unstable estimates.
Significantly improves the performance of the estimation algorithm in some cases, particularly when the time series are very persistent.
- Estimates not satisfying the usual stability condition for the regimes can now be allowed.
- Adjusted the step sizes in finite difference numerical differentiation.
- The step size in finite difference numerical differentiation can now be adjusted in the function iterate_more.
- Changed the random parameter generation for ind_Student models (estimation results with specific seeds are not backward compatible).
- A new function: filter_estimates, which can be used considers includes estimates that are not deemed inappropriate).
- A new function: plot_struct_shocks, which plots the structural shock time series.
- A new function: stvar_to_sstvars110, which makes STVAR models estimated with package versions <1.1.0 compatible with package versions >=1.1.0.
- Some adjustments to estimation with fitSTVAR. NOTE: estimation results with a particular seed may be different to the earlier version.
- Removed the argument "filter_estimates" from fitSTVAR as a redundancy (it is now always applied), since the function alt_stvar can in
any case be used to browse the estimates from any estimation round.
- Added a new functionality to fitSSTVAR: structural models identified by non-Gaussianity can be estimated based on different orderings
or signs of the columns of any of B_1,...,B_M (to conveniently examine models corresponding to various orderings and signs in the presence
of weak identification with respect to ordering or signs of the columns of B_2,...,B_M)
- Fixed a bug in the simulation algorithm for models incorporating independent Student's t conditional distributions
(the variance of each structural shock was not scaled to one).
- Fixed a bug in the GIRF simulation algorithm: the transition weights were not necessarily high for 'init_regime' at impact (but
the initial values were generated from the correct regimes).
- Made the function profile_logliks more user friendly.
- Added a simplified table of contents to the vignette.
- The argument standard_error_print can now be used directly in the summary-function to obtain printout of standard errors.
- Updated the documentation.
sstvars 1.0.2
- Updated readme.
- Updated documentation.
sstvars 1.0.1 (2024-05-29)
- Updated configure script to fix an issue with the installation on Mac OS X.
sstvars 1.0.0 (2024-05-27)