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Likelihood-based inference for Tobit confirmatory factor analysis using the multivariate Student-t distribution

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Abstract

Factor analysis models have been one of the most popular multivariate methods for data analysis among psychometricians, behavioral and educational researchers. But these models, originally developed for normally distributed observed variables, can be seriously affected by the presence of influential observations and censored data. Motivated by this situation, in this paper we propose a likelihood-based estimation for a multivariate Tobit confirmatory factor analysis model using the Student-t distribution (t-TCFA model). An EM-type algorithm is developed for computing the maximum likelihood estimates, obtaining as a byproduct the standard errors of the fixed effects and the exact likelihood value. Unlike other approaches proposed in the literature, our exact EM-type algorithm uses closed form expressions at the E-step based on the first two moments of a truncated multivariate Student-t distribution with the advantage that these expressions can be computed using standard statistical software. The performance of the proposed methods is illustrated through a simulation study and the analysis of a real dataset of early grade reading assessment test scores.

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Notes

  1. This type of censoring scheme relies on the assumption that the time the task was not sufficient to better estimate the responses of the students

References

  • Akaike, H.: A new look at the statistical model identification. IEEE Trans. Autom. Control 19, 716–723 (1974)

    Article  MATH  MathSciNet  Google Scholar 

  • Arellano-Valle, R.B., Bolfarine, H.: On some characterizations of the t-distribution. Stat. Probab. Lett. 25, 79–85 (1995)

    Article  MATH  MathSciNet  Google Scholar 

  • Arellano-Valle, R.B., Bolfarine, H., Lachos, V.H.: Skew-normal linear mixed models. J. Data Sci. 3, 415–438 (2005)

    Google Scholar 

  • Arellano-Valle, R.B., Genton, M.G.: Multivariate extended skew-t distributions and related families. Metron 68(3), 201–234 (2010)

    Article  MATH  MathSciNet  Google Scholar 

  • Azzalini, A., Genton, M.: Robust likelihood methods based on the skew-t and related distributions. Int. Stat. Rev. 76, 1490–1507 (2008)

    Article  Google Scholar 

  • Bozdogan, H.: Model selection and akaike’s information criterion (AIC): the general theory and its analytical extensions. Psychometrika 52(3), 345–370 (1987)

    Article  MATH  MathSciNet  Google Scholar 

  • Brown, T., Moore, M.: Confirmatory factor analysis. In: Hoyle, R.H. (ed.) Handbook of Structural Equation Modeling, pp. 361–379. Guilford Press, New York (2012)

    Google Scholar 

  • Costa, D.R., Lachos, V.H., Bazan, J.L., Azevedo, C.L.N.: Estimation methods for multivariate Tobit confirmatory factor analysis. Comput. Stat. Data Anal. 79, 248–260 (2014)

    Article  MathSciNet  Google Scholar 

  • Dempster, A., Laird, N., Rubin, D.: Maximum likelihood from incomplete data via the EM algorithm. J. R. Stat. Soc. B 39, 1–38 (1977)

    MATH  MathSciNet  Google Scholar 

  • DiStefano, C., Zhu, M., Mindrila, D.: Understanding and using factor scores: considerations for the applied researcher. Pract. Assess. Res. Eval. 14(20), 1–11 (2009)

    Google Scholar 

  • Genz, A., Bretz, F., Miwa, T., Mi, X., Leisch, F., Scheipl, F., Hothorn, T.: mvtnorm: Multivariate normal and t distributions. R package version 0.9-8 (2009). URL: http://CRAN.R-project.org/package=mvtnorm

  • Ho, H.J., Lin, T.-I., Chen, H.-Y., Wang, W.-L.: Some results on the truncated multivariate t distribution. J. Stat. Plan. Inference 142(1), 25–40 (2012)

    Article  MATH  MathSciNet  Google Scholar 

  • Jacqmin-Gadda, H., Thiebaut, R., Chene, G., Commenges, D.: Analysis of left-censored longitudinal data with application to viral load in HIV infection. Biostatistics 1(4), 355–368 (2000)

  • Kamakura, W.A., Wedel, M.: Exploratory Tobit factor analysis for multivariate censored data. Multivar. Behav. Res. 36, 53–82 (2001)

    Article  Google Scholar 

  • Lange, K.L., Little, R.J., Taylor, J.M.: Robust statistical modeling using the t distribution. J. Am. Stat. Assoc. 84(408), 881–896 (1989)

  • Lin, T.-I., Wu, P. H., McLachlan, G. J., Lee, S.X.: The skew-t factor analysis model. arXiv preprint arXiv:1310.5336 (2013)

  • Louis, T.: Finding the observed information matrix when using the EM algorithm. J. R. Stat. Soc. B 44, 226–233 (1982)

  • Lucas, A.: Robustness of the Student t based M-estimator. Commun. Stat. 26, 1165–1182 (1997)

    Article  MATH  Google Scholar 

  • Matos, L.A., Lachos, V.H., Balakrishnan, N., Labra, F.V.: Influence diagnostics in linear and nonlinear mixed-effects models with censored data. Comput. Stat. Data Anal. 57(1), 450–464 (2013a)

    Article  MathSciNet  Google Scholar 

  • Matos, L.A., Prates, M.O., H-Chen, M., Lachos, V.H.: Likelihood-based inference for mixed-effects models with censored response using the multivariate-t distribution. Statistica Sinica 23, 1323–1342 (2013b)

    MATH  MathSciNet  Google Scholar 

  • McLachlan, G., Bean, R.: Extension of the mixture of factor analyzers model to incorporate the multivariate \(t\)-distribution. Comput. Stat. Data Anal. 51, 5327–5338 (2007)

    Article  MATH  MathSciNet  Google Scholar 

  • Meng, X.L., Rubin, D.B.: Maximum likelihood estimation via the ECM algorithm: a general framework. Biometrika 80, 267–278 (1993)

    Article  MATH  MathSciNet  Google Scholar 

  • Muthén, B.O.: Tobit factor analysis. Br. J. Math. Stat. Psychol. 42, 241–250 (1989)

  • Prates, M.O., Costa, D.R., Lachos, V.H.: Generalized linear mixed models for correlated binary data with t-link. Stat. Comput. (2013). doi:10.1007/s11222-013-9423-3

  • R Core Team: R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria (2014). URL http://www.R-project.org

  • Schwarz, G.: Estimating the dimension of a model. Ann. Stat. 6(2), 461–464 (1978)

    Article  MATH  Google Scholar 

  • Vaida, F., Fitzgerald, A., DeGruttola, V.: Efficient hybrid EM for linear and nonlinear mixed effects models with censored response. Comput. Stat. Data Anal. 51(12), 5718–5730 (2007)

    Article  MATH  MathSciNet  Google Scholar 

  • Vaida, F., Liu, L.: Fast implementation for Normal mixed effects models with censored response. J. Comput. Graph. Stat. 18(4), 797–817 (2009)

    Article  MathSciNet  Google Scholar 

  • Wang, W., Lin, T.: An efficient ECM algorithm for maximum likelihood estimation in mixtures of \(t\)-factor analyzers. Comput. Stat. 28, 751–769 (2013)

  • Wu, L.: Mixed Effects Models for Complex Data. Chapman & Hall/CRC, Boca Raton (2010)

    MATH  Google Scholar 

  • Zhang, J., Li, J., Liu, C.: Robust factor analysis using the multivariate \(t\)-distribution. Statistica Sinica. 24, 291–312 (2014)

  • Zhou, X., Liu, X.: The Monte Carlo EM method for estimating multivariate Tobit latent variable models. J. Stat. Comput. Simul. 79, 1095–1107 (2009)

    Article  MATH  MathSciNet  Google Scholar 

  • Zhou, X., Tan, C.: Maximum likelihood estimation of Tobit factor analysis for multivariate t-distribution. Commun. Stat. 39, 1–16 (2010)

    Article  MATH  MathSciNet  Google Scholar 

Download references

Acknowledgments

The authors are grateful to the editor, associate editor and two anonymous reviewers for their valuable comments and suggestions that greatly improved this paper. We would also like to thank Dr. Jorge Bazán for supplying the EGRA data . The research of Luis M. Castro was supported by Grant FONDECYT 1130233 from the Chilean government and Grant 2012/19445-0 from FAPESP-Brazil. Denise Costa acknowledges support from CAPES-Brazil. Marcos Prates acknowledges support from CNPq and FAPEMIG-Brazil (Grant APQ-00570-13). The research of Victor Lachos was supported by FAPESP-Brazil (Grant 14/02938-9) and by CNPq-Brazil (Grant 305054/2011-2).

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Correspondence to Denise Reis Costa.

Appendices

Appendix A: Proofs of Propositions

Proof of Proposition 1

The proof of \((i)\) is straightforward from Equation (1). The proof of \((ii)\) follows from Proposition 4 given in Arellano-Valle and Genton (2010) by setting \(\lambda =\tau =0\).

Proof of Proposition 2

If \(\mathbf{X}\sim t_p(\varvec{\mu },\varvec{\varSigma },\nu )\), then we can write

$$\begin{aligned} \left( \displaystyle \frac{\nu +p}{\nu +\delta }\right) ^rt_p(\mathbf{x}|\varvec{\mu },\varvec{\varSigma },\nu )=c_p(\nu ,r)t_p(\mathbf{x}|\varvec{\mu },\varvec{\varSigma }^*,\nu +2r). \end{aligned}$$

Then, it follows that

$$\begin{aligned}&E\left\{ \displaystyle \left( \displaystyle \frac{\nu +p}{\nu +\delta }\right) ^r\mathbf{X}^{(k)}\right\} \\&\quad =c_p(\nu ,r)\frac{T_p(\mathbf{a}|\varvec{\mu },\varvec{\varSigma }^*,\nu +2r)}{T_{p}(\mathbf{a}|\varvec{\mu },\varvec{\varSigma },\nu )} \times \\&\qquad E\left\{ \mathbf{X}^{(k)}|\mathbf{X}\le \mathbf{a}\right\} \\&\qquad \mathrm{and} \,\,\ \int _{\mathbf{w}\le \mathbf{a}}\mathbf{w}^{(k)}\displaystyle \frac{t_p(\mathbf{w}|\varvec{\mu },\varvec{\varSigma }^*,\nu +2)}{T_{p}(\mathbf{a}|\varvec{\mu },\varvec{\varSigma },\nu )}d\mathbf{w}=\\&\qquad \displaystyle \frac{T_p(\mathbf{a}|\varvec{\mu },\varvec{\varSigma }^*,\nu +2)}{T_{p}(\mathbf{a}|\varvec{\mu },\varvec{\varSigma },\nu )}\int _{\mathbf{w}\le \mathbf{a}}\displaystyle \frac{t_p(\mathbf{w}|\varvec{\mu },\varvec{\varSigma }^*,\nu +2)}{T_{p}(\mathbf{a}|\varvec{\mu },\varvec{\varSigma }^*,\nu +2)}d\mathbf{w}, \end{aligned}$$

which concludes the proof.

Proof of Proposition 3

If \(\mathbf{X}\sim t_p(\varvec{\mu },\varvec{\varSigma },\nu )\), and using the result given in Proposition 1-\((ii)\), we have

$$\begin{aligned}&\left( \displaystyle \frac{\nu +p}{\nu +\delta }\right) ^rt_{p_2}\left( \mathbf{x}_2|\varvec{\mu }_{2.1},\widetilde{\varvec{\varSigma }}_{22.1},\nu +p_1\right) \\&= \frac{d_p(p_1,\nu ,r)}{(\nu +\delta _1)^r}{t_{p_2}(\mathbf{x_2}|\varvec{\mu }_{2.1},\widetilde{\varvec{\varSigma }}^*_{22.1},\nu +p_1+2r)} \end{aligned}$$

and the proof concludes by noting that

$$\begin{aligned}&E\left\{ \left( \displaystyle \frac{\nu +p}{\nu +\delta }\right) ^r\mathbf{X}_2^{(k)}|\mathbf{X}_1\right\} =\frac{d_p(p_1,\nu ,r)}{(\nu +\delta _1)^r} \times \\&\displaystyle \frac{T_{p_2}(\mathbf{a}^{x_2}|\varvec{\mu }_{2.1},\widetilde{\varvec{\varSigma }}^*_{22.1},\nu +p_1+2r)}{T_{p_2}(\mathbf{a}^{x_2}|\varvec{\mu }_{2.1},\widetilde{\varvec{\varSigma }}_{22.1},\nu +p_1)}E\left\{ \mathbf{X}_2^{(k)}|\mathbf{X}_2\le \mathbf{a}^{x_2}\right\} , \end{aligned}$$

where \(\mathbf{X}_2\sim t_{p_2}\left( \varvec{\mu }_{2.1},\widetilde{\varvec{\varSigma }}^*_{22.1},\nu +p_1+2r \right) .\)

Appendix B: Details of the EM algorithm

First, we introduce Lemma 1, which used in our procedures. Its proof can be found in Arellano-Valle et al. (2005).

Lemma 1

Let \(\mathbf{Y}\sim N_p(\varvec{\mu },\varvec{\varSigma })\) and \( \mathbf{x}\sim N_q(\varvec{\eta },\varvec{\varOmega })\). So,

$$\begin{aligned}&\phi _p(\mathbf{y}|\varvec{\mu }+ \mathbf{A}x,\varvec{\varSigma })\phi _q(x|\varvec{\eta },\varvec{\varOmega }) \\&\quad = \phi _p(\mathbf{y}|\varvec{\mu }+ \mathbf{A}\varvec{\eta }, \varvec{\varSigma }+ \mathbf{A}\varvec{\varOmega }\mathbf{A}^{\top } )\\&\qquad \times \, \phi _q(x|\varvec{\eta }+ \varvec{\varLambda }\mathbf{A}^{\top }\varvec{\varSigma }^{-1}(\mathbf{y}-\varvec{\mu }-\mathbf{A}\varvec{\eta }),\varvec{\varLambda }), \end{aligned}$$

where \(\varvec{\varLambda }= (\varvec{\varOmega }^{-1} + \mathbf{A}^{\top }\varvec{\varSigma }^{-1}\mathbf{A})^{-1}\).

The derivatives of the function \(Q(\varvec{\theta }|\varvec{\theta }^{(k)}\) with respect to \(\varvec{\beta }\), \(\varvec{\varLambda }\) and \(\varvec{\varPsi }\) leads to

$$\begin{aligned} \displaystyle \frac{\partial Q(\varvec{\theta }|\varvec{\theta }^{(k)})}{\partial \varvec{\beta }}&= - \sum ^n_{i=1}\left[ -\widehat{u_i\mathbf{y}_i}^{(k)}\,\mathbf{X}_i^{\top }+\widehat{u_i}^{(k)}\varvec{\beta }\mathbf{X}_i^{\top }\mathbf{X}_i \right. \\&\left. +\,\varvec{\varLambda }\widehat{u_i\mathbf{z}_i}^{(k)}\mathbf{X}_i \right] ,\\ \displaystyle \frac{\partial Q(\varvec{\theta }|\varvec{\theta }^{(k)})}{\partial \varvec{\varLambda }}&= -\sum ^n_{i=1}\left[ \widehat{u_i\mathbf{z}_i}^{(k)} \varvec{\beta }^{\top }\mathbf{X}_i^{\top }-\widehat{u_i\mathbf{y}_i\mathbf{z}_i^{\top }}^{(k)} \right. \\&\left. +\,\varvec{\varLambda }\widehat{u_i\mathbf{z}_i\mathbf{z}_i^{\top }}^{(k)}\right] \\ \displaystyle \frac{\partial Q(\varvec{\theta }|\varvec{\theta }^{(k)})}{\partial \varvec{\varPsi }}&= \sum ^n_{i=1}\left[ \varvec{\varPsi }^{-1}-\varvec{\varPsi }^{-2}\widehat{B_i}^{(k)}\right] , \end{aligned}$$

where

$$\begin{aligned} \widehat{B}^{(k)}_i&= \mathrm{tr}(\widehat{u_i\mathbf{y}_i\mathbf{y}_i^{\top }}^{(k)})- \widehat{u_i\mathbf{y}}_i^{\top (k)}\mathbf{X}_i\varvec{\beta }-\mathrm{tr}(\widehat{u_i\mathbf{y}_i \mathbf{z}_i^{\top }}^{(k)}\varvec{\varLambda })\\&-\varvec{\beta }^{\top }\mathbf{X}_i^{\top }\widehat{u_i\mathbf{y}_i}^{(k)}+\varvec{\beta }^{\top } \mathbf{X}_i^{\top }\widehat{u_i}^{(k)}\mathbf{X}_i\varvec{\beta }\\&+\varvec{\beta }^{\top }\mathbf{X}_i^{\top }\varvec{\varLambda }\widehat{u_i\mathbf{z}_i}^{(k)}- \mathrm{tr}(\widehat{u_i\mathbf{y}_i\mathbf{z}_i^{\top }}^{(k)}\varvec{\varLambda }^{\top })\\&+\widehat{u_i\mathbf{z}_i}^{\top (k)}\varvec{\varLambda }^{\top }\mathbf{X}_i\varvec{\beta }+ \mathrm{tr}(\widehat{u_i\mathbf{z}_i\mathbf{z}_i^{\top }}^{(k)}\varvec{\varLambda }^{\top }\varvec{\varLambda }). \end{aligned}$$

The solution of these derivatives at zero gives the estimates of the MLE presented in (8)–(10).

Appendix C: Complementary results of the simulation study

Figures 10 and 11 present the absolute bias and the MSE of \(\lambda _{42}\), \(\varPsi _{33}\) and \(\varPsi _{44}\).

Fig. 10
figure 10

Simulated data. Absolute bias and MSE for the parameter \(\lambda _{42}\) under scenario 3

Fig. 11
figure 11

Simulated data. Absolute bias and MSE for the parameters \(\varPsi _{33}\) (first row) and \(\varPsi _{44}\) (second row) under scenario 3

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Castro, L.M., Costa, D.R., Prates, M.O. et al. Likelihood-based inference for Tobit confirmatory factor analysis using the multivariate Student-t distribution. Stat Comput 25, 1163–1183 (2015). https://doi.org/10.1007/s11222-014-9502-0

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