REVIEW 4 minor 99 references
An R package that turns dynamic quantile linear models into an integrated Bayesian workflow: specify, fit with MCMC or fast variational Bayes, forecast, and diagnose from one object.
Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →
T0 review · deepseek-v4-flash
2026-08-01 06:33 UTC pith:OGWZCVCQ
load-bearing objection A solid, honest software paper—LDVB is the new piece, the package looks usable, but the benchmark is a single seed and LDVB interval accuracy is never checked against MCMC.
exdqlm: An R Package for Estimation and Analysis of Flexible Dynamic Quantile Linear Models
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The core discovery is that the exAL-based exDQLM can be delivered as a practical, unified software workflow. The exAL distribution is defined so that the mass of the error below zero equals the target quantile p0, making the state contribution F_t^T θ_t the p0-quantile of the response. The exAL admits a hierarchical latent-variable representation that turns the observation equation into a Gaussian one conditional on latent variables; this property is what lets the package reuse standard Kalman recursions for the state sequence while handling the nonconjugate scale–skewness block with slice sampling or a Laplace-delta variational approximation. The paper demonstrates the workflow on Lake Huro
What carries the argument
The central object is the extended asymmetric Laplace (exAL) distribution, a parametric generalization of the asymmetric Laplace family with a skewness parameter γ restricted to an interval determined by p0. Its defining property, that the integral of the exAL density from −∞ to 0 equals p0, makes any linear combination F_t^T θ_t in the observation equation equal to the p0-quantile of the response. The exAL has a mixture representation over two latent variables—an exponential v_t and a positive truncated normal s_t—so conditional on these, the observation error is Gaussian. This turns posterior inference into a standard Gaussian state-space problem for the latent state, with the scale and sk
Load-bearing premise
The claim that the fitted state is the p0-quantile of the response rests entirely on the exAL distribution's property that the mass below zero equals p0; if that property or the mixture representation behind it fails for some parameter values, the model's quantile interpretation collapses.
What would settle it
Compute the integral of the exAL density from −∞ to 0 to high precision across a dense grid of p0 and γ within the admissible interval (L,U); a deviation from p0 anywhere would invalidate the quantile interpretation. Alternatively, simulate from the mixture representation and check that the empirical proportion of values ≤0 converges to p0; a mismatch would show the augmentation used by MCMC and LDVB is not faithful.
If this is right
- Users can obtain time-varying quantile estimates, credible intervals, and k-step-ahead forecasts from a single fitted object, choosing between full MCMC and the faster LDVB approximation.
- Transfer-function specifications allow covariates to affect a quantile through a decaying lag structure, with a summary of the decay horizon reported as median.kt.
- Separately fitted quantile models can be combined into one posterior predictive distribution via quantileSynthesis(), with optional monotonicity corrections for quantile crossing.
- CRPS, PPLC, PIT, and KL diagnostics give a reproducible basis for comparing models and selecting discount factors.
- Static AL/exAL regression with shrinkage priors is supported through the same interface, with LDVB running substantially faster than MCMC in the presented benchmark.
Where Pith is reading between the lines
- A natural extension the paper leaves implicit is to let the transfer-function decay rate λ be estimated with a prior rather than selected from a fixed grid; the package's fixed-λ workflow could be amended with a joint Bayesian update.
- The large LDVB speed advantage suggests it could be promoted from initialization to a default model-screening tool, with MCMC reserved for final tail-sensitive inference; the paper only uses LDVB as a warm start.
- The exAL augmentation may carry over to multivariate or nonlinear dynamic quantile models, since the latent-mixture trick that linearizes the observation equation is not tied to the linear state-space form.
- Diagnostic-based discount-factor selection could be formalized as continuous optimization over the discount-factor space, a modest extension of the coarse-grid scan demonstrated in the sunspot example.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper presents the R package exdqlm, which implements Bayesian quantile regression with a focus on dynamic state-space models. The package is built around the extended asymmetric Laplace (exAL) distribution and the extended dynamic quantile linear model (exDQLM) framework, providing MCMC and Laplace-delta variational Bayes (LDVB) inference, transfer-function state augmentation, static exAL/AL regression with shrinkage priors, forecasting, posterior-predictive synthesis, and diagnostics. The manuscript describes the model formulation, package design, and four worked examples, with appendices collecting posterior targets and implementation details. The central claim is that exdqlm fills a practical gap between general quantile-regression software and Gaussian state-space software by supplying a dedicated Bayesian dynamic quantile workflow.
Significance. If the claims are correct, the package is a useful and well-scoped software contribution. Its main strengths are transparency and reproducibility: the posterior targets in Appendices A-F are coherent, the examples exercise the claimed interfaces, the limitations of LDVB, one-quantile-at-a-time fitting, and post hoc synthesis are explicitly stated, and the replication scripts, seeds, and backend profiles are documented. The paper does not introduce new statistical theory; rather, it packages and integrates methods from Yan et al. (2025) and Barata et al. (2022) into a usable R workflow. This is appropriate for a Journal of Statistical Software submission, and the paper clearly delineates the package's niche relative to existing quantile-regression and state-space software.
minor comments (4)
- [Section 2.1, Eq. (3) / Appendix A.1] The central quantile interpretation rests on the imported exAL property that the CDF of the exAL density at the location parameter equals p0 over the admissible gamma interval. Since this property is load-bearing and the package exposes dexal(), pexal(), qexal(), and rexal(), the manuscript would be strengthened by a small numerical verification that the implemented density/CDF/quantile functions are mutually consistent and that the stated integral identity holds over a grid of (p0, sigma, gamma). This is a verification gap, not a demonstrated error.
- [Section 2.2, Eqs. (11)-(12)] The PIT, standardized forecast errors, and KL diagnostics are computed under a Gaussian MAP plug-in approximation to the one-step-ahead predictive distribution. Because the exAL/AL error distribution is non-Gaussian, these diagnostics can reflect the approximation error as well as model misfit. The text already calls them 'diagnostic summaries,' but I recommend an explicit sentence noting that the exact PIT would require integration over latent variables and parameters, and that the reported values are approximate calibration summaries.
- [Section 4.4, Table 10] The static simulation benchmark uses a single data realization, so the reported differences between LDVB and MCMC (e.g., active RMSE 0.264 vs 0.168 at p0=0.25) may be within Monte Carlo noise. Adding repeated-seed summaries with standard errors or boxplots would make the benchmark claims more robust and would better support the qualitative statement that LDVB is a useful first-pass screen.
- [Section 4.2, Table 7 and Section 4.4] The LDVB-vs-MCMC comparison focuses on point summaries, predictive scores, and runtimes. Since one of the package's advertised features is approximate posterior uncertainty quantification, it would be informative to include at least one quantitative comparison of LDVB and MCMC credible intervals, such as interval lengths or coverage in a repeated-setting simulation. This would help users calibrate their expectations when using LDVB for interval summaries.
Circularity Check
No circularity: software contribution built on cited external and prior work, with held-out and known-target validation.
full rationale
The paper's stated contribution is software-centered: it packages the exAL family of Yan et al. (2025) and the exDQLM framework of Barata et al. (2022) into an integrated R workflow. The exAL mixture representation (Eq. 3) and the quantile identity are imported from external published work, not rederived as a new result, so there is no self-definitional step in the paper itself. The exDQLM state-space formulation comes from prior work by two of the current authors, but it is presented as a foundation, not as an external uniqueness theorem, and the current paper's claims concern package capability rather than a new derivation. No fitted input is relabeled as a prediction: discount-factor selection using CRPS is explicitly described as in-sample diagnostic screening; the transfer-function rate lambda is selected on training-period PPLC and then evaluated on a held-out 18-month window; the static simulation benchmark compares estimates to a known sparse quantile signal on an independent holdout. Limitations such as LDVB approximation, one-quantile-at-a-time fitting, post hoc synthesis, and fixed lambda are disclosed in Section 5. The only nontrivial imported premise is the exAL CDF property from Yan et al. (2025); that is a verification gap external to this paper, not a circular reduction.
Axiom & Free-Parameter Ledger
free parameters (5)
- Transfer rate lambda =
0.85
- Seasonal discount factor (sunspot example) =
0.85
- Trend discount factor (examples) =
0.9
- Prior hyperparameters (a_sig, b_sig, m_gam, s_gam, df_gam) =
defaults (2.1, 1.1, 0, 1, 1)
- Initial state prior m0 =
e.g., 579 for Lake Huron, 50 for sunspots
axioms (4)
- domain assumption The exAL error distribution satisfies the quantile property ∫_{-∞}^0 exAL_{p0}(ε|0,σ,γ)dε = p0 and admits the mixture representation in Eq. (3).
- standard math Conditional on latent variables, the exDQLM becomes a Gaussian state-space model, so standard Kalman filtering, smoothing, and backward-sampling recursions are valid.
- domain assumption The Laplace-delta variational approximation of Wang and Blei (2013) yields accurate posterior moments for the nonconjugate (σ,γ) block.
- ad hoc to paper The one-step-ahead predictive distribution used in diagnostics is adequately approximated by a Gaussian with MAP plug-in moments.
read the original abstract
We present the R package exdqlm for Bayesian quantile regression, with primary emphasis on dynamic state-space quantile models for time series. The package is built around extended dynamic quantile linear models (exDQLMs), which use the extended asymmetric Laplace (exAL) family, a parametric extension of the asymmetric Laplace (AL) distribution commonly used in quantile regression. The software provides posterior simulation via Markov chain Monte Carlo (MCMC) and fast approximate posterior inference via Laplace-delta variational Bayes (LDVB), supporting posterior uncertainty quantification while also providing a computationally efficient option for longer time series. The same package interface supports static exAL quantile regression with regularized priors, dynamic transfer-function models for nonlinear input effects at a given quantile, post hoc posterior-predictive synthesis across separately fitted quantiles, forecasting, and quantitative and visual diagnostics for model evaluation.
Figures
Reference graph
Works this paper leans on
-
[1]
Barata R, Prado R, Sans\' o B (2022). Fast inference for time-varying quantiles via flexible dynamic models with application to the characterization of atmospheric rivers . The Annals of Applied Statistics, 16(1), 247--271. doi:10.1214/21-AOAS1497
-
[2]
Statistical Inference Under Order Restrictions: The Theory and Application of Isotonic Regression
Barlow RE, Bartholomew DJ, Bremner JM, Brunk HD (1972). Statistical Inference Under Order Restrictions: The Theory and Application of Isotonic Regression. John Wiley & Sons, New York
1972
-
[3]
bayesQR : Bayesian Quantile Regression
Benoit D, Al-Hamzawi R, Yu K, Van den Poel D (2023). bayesQR : Bayesian Quantile Regression . R package version 2.4, ://CRAN.R-project.org/package=bayesQR
2023
-
[4]
brms : Special Family Functions for brms Models
B \"u rkner PC (2026). brms : Special Family Functions for brms Models . Package documentation, accessed 2026-04-19, ://paulbuerkner.com/brms/reference/brmsfamily.html
2026
-
[5]
On Gibbs sampling for state space models
Carter CK, Kohn R (1994). On Gibbs sampling for state space models. Biometrika, 81(3), 541--553
1994
-
[6]
Quantile and Probability Curves Without Crossing
Chernozhukov V, Fern \'a ndez-Val I, Galichon A (2010). Quantile and Probability Curves Without Crossing. Econometrica, 78(3), 1093--1125. doi:10.3982/ECTA7880
doi:10.3982/ecta7880 2010
-
[7]
pqrBayes : Bayesian Penalized Quantile Regression
Fan K, Wu C, Ren J, Li X, Zhou F (2026). pqrBayes : Bayesian Penalized Quantile Regression . R package version 1.2.1, ://CRAN.R-project.org/package=pqrBayes
2026
-
[8]
qgam : Smooth Additive Quantile Regression Models
Fasiolo M, Griffiths B (2025). qgam : Smooth Additive Quantile Regression Models . R package version 2.0.0, ://CRAN.R-project.org/package=qgam
2025
-
[9]
Data augmentation and dynamic linear models
Fr \"u hwirth-Schnatter S (1994). Data augmentation and dynamic linear models. Journal of time series analysis, 15(2), 183--202
1994
-
[10]
qrcm : Quantile Regression Coefficients Modeling
Frumento P (2025). qrcm : Quantile Regression Coefficients Modeling . R package version 3.2, ://CRAN.R-project.org/package=qrcm
2025
-
[11]
lqr : Robust Linear Quantile Regression
Galarza CE, Benites L, Bourguignon M, Lachos VH (2024). lqr : Robust Linear Quantile Regression . R package version 5.2, ://CRAN.R-project.org/package=lqr
2024
-
[12]
Model choice: a minimum posterior predictive loss approach
Gelfand AE, Ghosh SK (1998). Model choice: a minimum posterior predictive loss approach. Biometrika, 85(1), 1--11
1998
-
[13]
Strictly Proper Scoring Rules, Prediction, and Estimation
Gneiting T, Raftery AE (2007). Strictly Proper Scoring Rules, Prediction, and Estimation. Journal of the American Statistical Association, 102(477), 359--378. doi:10.1198/016214506000001437
-
[15]
conquer : Convolution-Type Smoothed Quantile Regression
He X, Pan X, Tan KM, Zhou WX (2023). conquer : Convolution-Type Smoothed Quantile Regression . R package version 1.3.3, ://CRAN.R-project.org/package=conquer
2023
-
[16]
Time series modeling via hierarchical mixtures
Huerta G, Jiang W, Tanner MA (2003). Time series modeling via hierarchical mixtures. Statistica Sinica, pp. 1097--1118
2003
-
[17]
Quantile regression
Koenker R (2005). Quantile regression. Cambridge University Press, New York
2005
-
[18]
quantreg : Quantile Regression
Koenker R (2025). quantreg : Quantile Regression . R package version 6.1, ://CRAN.R-project.org/package=quantreg
2025
-
[19]
Bayesian semiparametric modelling in quantile regression
Kottas A, Krnjaji \'c M (2009). Bayesian semiparametric modelling in quantile regression. Scandinavian Journal of Statistics, 36(2), 297--319
2009
-
[20]
Gibbs sampling methods for B ayesian quantile regression
Kozumi H, Kobayashi G (2011). Gibbs sampling methods for B ayesian quantile regression. Journal of statistical computation and simulation, 81(11), 1565--1578
2011
-
[21]
On information and sufficiency
Kullback S, Leibler RA (1951). On information and sufficiency. The annals of mathematical statistics, 22(1), 79--86
1951
-
[22]
Verification Tools for Probabilistic Forecasts of Continuous Hydrological Variables
Laio F, Tamea S (2007). Verification Tools for Probabilistic Forecasts of Continuous Hydrological Variables. Hydrology and Earth System Sciences, 11(4), 1267--1277. doi:10.5194/hess-11-1267-2007
-
[23]
quantregGrowth : Non-Crossing Additive Regression Quantiles and Non-Parametric Growth Charts
Muggeo VMR (2025). quantregGrowth : Non-Crossing Additive Regression Quantiles and Non-Parametric Growth Charts . R package version 1.7-2, ://CRAN.R-project.org/package=quantregGrowth
2025
-
[24]
Neal RM (2003). Slice sampling. The Annals of Statistics, 31(3), 705--767. doi:10.1214/aos/1056562461
arXiv 2003
-
[25]
Nishimura A, Suchard MA (2023). Shrinkage with shrunken shoulders: Gibbs sampling shrinkage model posteriors with guaranteed convergence rates. Bayesian Analysis, 18(2), 367--390. doi:10.1214/22-BA1308
-
[26]
Climate Indices: Monthly Atmospheric and Ocean Time Series
NOAA Physical Sciences Laboratory (2026). Climate Indices: Monthly Atmospheric and Ocean Time Series. ://psl.noaa.gov/data/climateindices/
2026
-
[27]
dynr : Dynamic Models with Regime-Switching
Ou L, Hunter M, Chow SM, Ji L, Chen M, Hung HJ, Lee J, Li Y, Park J (2021). dynr : Dynamic Models with Regime-Switching . R package version 0.1.16-2, ://CRAN.R-project.org/package=dynr
2021
-
[28]
dlm : Bayesian and Likelihood Analysis of Dynamic Linear Models
Petris G, Gilks W (2018). dlm : Bayesian and Likelihood Analysis of Dynamic Linear Models . R package version 1.1-5, ://CRAN.R-project.org/package=dlm
2018
-
[29]
CODA: Convergence Diagnosis and Output Analysis for MCMC
Plummer M, Best N, Cowles K, Vines K (2006). CODA: Convergence Diagnosis and Output Analysis for MCMC. R News, 6(1), 7--11. ://journal.r-project.org/archive/
2006
-
[30]
Time Series: Modeling, Computation and Inference
Prado R, Ferreira MA, West M (2021). Time Series: Modeling, Computation and Inference. 2nd edition. Chapman and Hall/CRC Press
2021
-
[31]
Multivariate time series modeling and classification via hierarchical VAR mixtures
Prado R, Molina F, Huerta G (2006). Multivariate time series modeling and classification via hierarchical VAR mixtures. Computational Statistics & Data Analysis, 51(3), 1445--1462
2006
-
[32]
R: A Language and Environment for Statistical Computing
R Core Team (2026). R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. ://www.R-project.org/
2026
-
[33]
Flexible B ayesian quantile regression for independent and clustered data
Reich BJ, Bondell HD, Wang HJ (2009). Flexible B ayesian quantile regression for independent and clustered data. Biostatistics, 11(2), 337--352
2009
-
[34]
Remarks on a multivariate transformation
Rosenblatt M (1952). Remarks on a multivariate transformation. The annals of mathematical statistics, 23(3), 470--472
1952
-
[35]
rqPen : Penalized Quantile Regression
Sherwood B, Li S, Maidman A (2026). rqPen : Penalized Quantile Regression . R package version 4.2, ://CRAN.R-project.org/package=rqPen
2026
-
[36]
A B ayesian nonparametric approach to inference for quantile regression
Taddy MA, Kottas A (2010). A B ayesian nonparametric approach to inference for quantile regression. Journal of Business & Economic Statistics, 28(3), 357--369
2010
-
[37]
qrjoint : Joint Estimation in Linear Quantile Regression
Tokdar S, Cunningham E (2025). qrjoint : Joint Estimation in Linear Quantile Regression . R package version 2.0-11, ://CRAN.R-project.org/package=qrjoint
2025
-
[38]
National Water Information System data available on the World Wide Web (USGS Water Data for the Nation)
US Geological Survey (2016). National Water Information System data available on the World Wide Web (USGS Water Data for the Nation). ://waterdata.usgs.gov/nwis/
2016
-
[39]
Modern Applied Statistics with S
Venables WN, Ripley BD (2002). Modern Applied Statistics with S . Fourth edition. Springer, New York. ISBN 0-387-95457-0, ://www.stats.ox.ac.uk/pub/MASS4/
2002
-
[40]
Variational Inference in Nonconjugate Models
Wang C, Blei DM (2013). Variational Inference in Nonconjugate Models. Journal of Machine Learning Research, 14, 1005--1031. ://jmlr.org/papers/v14/wang13b.html
2013
-
[41]
Bayesian Forecasting and Dynamic Models
West M, Harrison J (1997). Bayesian Forecasting and Dynamic Models. 2 edition. Springer, New York. doi:10.1007/b98971
-
[42]
A New Family of Error Distributions for Bayesian Quantile Regression
Yan Y, Zheng X, Kottas A (2025). A New Family of Error Distributions for Bayesian Quantile Regression. Bayesian Analysis. doi:10.1214/25-BA1507
-
[43]
Bayesian quantile regression
Yu K, Moyeed RA (2001). Bayesian quantile regression. Statistics & Probability Letters, 54(4), 437--447
2001
-
[44]
2026 , url =
R: A Language and Environment for Statistical Computing , author =. 2026 , url =
2026
-
[45]
R News , year =
CODA: Convergence Diagnosis and Output Analysis for MCMC , author =. R News , year =
-
[46]
W. N. Venables and B. D. Ripley , publisher =. Modern Applied Statistics with. 2002 , note =
2002
-
[47]
Taddy, Matthew A and Kottas, Athanasios , journal=. A. 2010 , publisher=
2010
-
[48]
, title =
Gneiting, Tilmann and Raftery, Adrian E. , title =. Journal of the American Statistical Association , volume =. 2007 , doi =
2007
-
[49]
Prado and M
R. Prado and M. A. Ferreira and M. West , year=. Time Series: Modeling, Computation and Inference , publisher=
-
[50]
Hydrology and Earth System Sciences , volume =
Laio, Francesco and Tamea, Stefania , title =. Hydrology and Earth System Sciences , volume =. 2007 , doi =
2007
-
[51]
Journal of Mathematical Psychology , volume=
A tutorial on variational Bayes for latent linear stochastic time-series models , author=. Journal of Mathematical Psychology , volume=. 2014 , publisher=
2014
-
[52]
2003 , school=
Variational algorithms for approximate Bayesian inference , author=. 2003 , school=
2003
-
[53]
Scandinavian Journal of Statistics , volume=
Bayesian semiparametric modelling in quantile regression , author=. Scandinavian Journal of Statistics , volume=. 2009 , publisher=
2009
-
[54]
Flexible
Reich, Brian J and Bondell, Howard D and Wang, Huixia J , journal=. Flexible. 2009 , publisher=
2009
-
[55]
Benoit, Dries and Al-Hamzawi, Rahim and Yu, Keming and Van den Poel, Dirk , year =
-
[56]
Fan, Kun and Wu, Cen and Ren, Jie and Li, Xiaoxi and Zhou, Fei , year =
-
[57]
Statistical Inference Under Order Restrictions: The Theory and Application of Isotonic Regression , author =
-
[58]
Quantile and Probability Curves Without Crossing , journal =
Chernozhukov, Victor and Fern. Quantile and Probability Curves Without Crossing , journal =. 2010 , doi =
2010
-
[59]
Biometrika , volume=
On Gibbs sampling for state space models , author=. Biometrika , volume=. 1994 , publisher=
1994
-
[60]
Journal of time series analysis , volume=
Data augmentation and dynamic linear models , author=. Journal of time series analysis , volume=. 1994 , publisher=
1994
-
[61]
Solar Minimum; Solar Maximum , year =
Karen Fox , journal =. Solar Minimum; Solar Maximum , year =
-
[62]
2016 , url =
National Water Information System data available on the World Wide Web (USGS Water Data for the Nation) , title =. 2016 , url =
2016
-
[63]
Journal of Geophysical Research: Atmospheres , volume=
Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century , author=. Journal of Geophysical Research: Atmospheres , volume=. 2003 , publisher=
2003
-
[64]
Climate Indices: Monthly Atmospheric and Ocean Time Series , year =
-
[65]
Journal of Statistical Software , volume=
bayesQR: A Bayesian approach to quantile regression , author=. Journal of Statistical Software , volume=
-
[66]
Giovanni Petris and Wally Gilks , year =
-
[67]
Lu Ou and Michael Hunter and Sy-Min Chow and Linying Ji and Meng Chen and Hui-Ju Hung and Jungmin Lee and Yanling Li and Jonathan Park , year =
-
[68]
Striaukas, Jonas , year =
-
[69]
He, Xuming and Pan, Xiaoou and Tan, Kean Ming and Zhou, Wen-Xin , year =
-
[70]
Fasiolo, Matteo and Griffiths, Ben , year =
-
[71]
and Benites, Luis and Bourguignon, Marcelo and Lachos, Victor H
Galarza, Christian E. and Benites, Luis and Bourguignon, Marcelo and Lachos, Victor H. , year =
-
[72]
Journal of Statistical Software , volume=
An R package for dynamic linear models , author=. Journal of Statistical Software , volume=
-
[73]
Koenker, Roger , year =
-
[74]
Muggeo, Vito M. R. , year =
-
[75]
Frumento, Paolo , year =
-
[76]
Tokdar, Surya and Cunningham, Erika , year =
-
[77]
, year =
Xu, Steven and Reich, Brian J. , year =
-
[78]
R package version 5.05 , author=
quantreg: Quantile Regression. R package version 5.05 , author=. R Foundation for Statistical Computing: Vienna) Available at: http://CRAN. R-project. org/package= quantreg , year=
-
[79]
Sherwood, Ben and Li, Shaobo and Maidman, Adam , year =
-
[80]
Fogarty, Ben , year =
-
[81]
2026 , note =
Working with Quantile Regression Models , author =. 2026 , note =
2026
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.