<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0120-1751</journal-id>
<journal-title><![CDATA[Revista Colombiana de Estadística]]></journal-title>
<abbrev-journal-title><![CDATA[Rev.Colomb.Estad.]]></abbrev-journal-title>
<issn>0120-1751</issn>
<publisher>
<publisher-name><![CDATA[Departamento de Estadística - Universidad Nacional de Colombia.]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0120-17512008000200004</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Modelo factorial dinámico threshold]]></article-title>
<article-title xml:lang="en"><![CDATA[Threshold Dynamic Factor Model]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[CORREAL]]></surname>
<given-names><![CDATA[MARÍA ELSA]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[PEÑA]]></surname>
<given-names><![CDATA[DANIEL]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad de los Andes Departamento de Ingeniería Industrial ]]></institution>
<addr-line><![CDATA[Bogotá ]]></addr-line>
<country>Colombia</country>
</aff>
<aff id="A02">
<institution><![CDATA[,Universidad Carlos III de Madrid Departamento de Estadística y Economía ]]></institution>
<addr-line><![CDATA[Madrid ]]></addr-line>
<country>España</country>
</aff>
<pub-date pub-type="pub">
<day>15</day>
<month>12</month>
<year>2008</year>
</pub-date>
<pub-date pub-type="epub">
<day>15</day>
<month>12</month>
<year>2008</year>
</pub-date>
<volume>31</volume>
<numero>2</numero>
<fpage>183</fpage>
<lpage>192</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S0120-17512008000200004&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S0120-17512008000200004&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S0120-17512008000200004&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[En este artículo se introduce el modelo factorial dinámico threshold, el cual permite analizar sistemas de series temporales que presenten comportamientos no lineales del tipo umbral. Se propone un método de estimación que combina el algoritmo EM con un procedimiento de búsqueda directa utilizando los algoritmos del filtro y de suavización de Kalman. El procedimiento estima factores comunes con comportamientos que cambian de régimen de acuerdo con una variable umbral.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[This paper introduces a threshold dynamic factor model for the analysis of vector time series which shows non-linear behavior of threshold type. We propose an estimation procedure combining an EM algorithm with a grid search procedure by the ways of the Kalman filter and smoothing recursions. We estimate common latent threshold factors that may explain the dynamic relationships within the group of variables.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[series de tiempo no lineales]]></kwd>
<kwd lng="es"><![CDATA[análisis factorial]]></kwd>
<kwd lng="es"><![CDATA[modelo threshold]]></kwd>
<kwd lng="es"><![CDATA[algoritmo EM]]></kwd>
<kwd lng="es"><![CDATA[filtro de Kalman]]></kwd>
<kwd lng="en"><![CDATA[Nonlinear time series]]></kwd>
<kwd lng="en"><![CDATA[Factor analysis]]></kwd>
<kwd lng="en"><![CDATA[Threshold model]]></kwd>
<kwd lng="en"><![CDATA[EM algorithm]]></kwd>
<kwd lng="en"><![CDATA[Kalman filter]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[ 
<font size="2" face="verdana">

    <p>
<b>
<font size="4">
    <center>
Modelo factorial din&aacute;mico <i>threshold</i>
</center>
</font>
</b>
</p>

    <p>
<b>
<font size="3">
    <center>
Threshold Dynamic Factor Model
</center>
</font>
</b>
</p>

    <p>
    <center>
MAR&Iacute;A ELSA CORREAL<sup>1</sup>, 
DANIEL PE&Ntilde;A<sup>2</sup>
</center>
</p>

    <p>
<sup>1</sup>Universidad de los Andes, Departamento de Ingenier&iacute;a Industrial, Bogot&aacute;, Colombia. Profesora asociada. Email: <a href="mailto:mcorreal@uniandes.edu.co">mcorreal@uniandes.edu.co</a>
    <br>

<sup>2</sup>Universidad Carlos III de Madrid, Departamento de Estad&iacute;stica y Econom&iacute;a, Madrid, Espa&ntilde;a. Profesor catedr&aacute;tico. Email: <a href="mailto:dpena@est-econ.uc3m.es">dpena@est-econ.uc3m.es</a>
    <br>
</p>

<hr size="1">

    ]]></body>
<body><![CDATA[<p>
<b>
    <center>
Resumen
</center>
</b>
</p>

    <p>
En este art&iacute;culo se introduce el modelo factorial din&aacute;mico <i>threshold</i>, el cual permite analizar sistemas de series temporales que presenten comportamientos no lineales del tipo umbral. Se propone un m&eacute;todo de estimaci&oacute;n que combina el algoritmo EM con un procedimiento de b&uacute;squeda directa utilizando los algoritmos del filtro y de suavizaci&oacute;n de Kalman. El procedimiento estima factores comunes con comportamientos que cambian de r&eacute;gimen de acuerdo con una variable umbral.
</p>

    <p>
<b>
Palabras clave:
</b>
series de tiempo no lineales,
an&aacute;lisis factorial,
modelo threshold,
algoritmo EM,
filtro de Kalman.
</p>

<hr size="1">

    <p>
<b>
    <center>
Abstract
</center>
</b>
</p>

    <p>
This paper introduces a threshold dynamic factor model for the analysis of vector time series which shows non-linear behavior of threshold type. We propose an estimation procedure combining an EM algorithm with a grid search procedure by the ways of the Kalman filter and smoothing recursions. We estimate common latent threshold factors that may explain the dynamic relationships within the group of variables.
</p>

    <p>
<b>
Key words:
</b>
Nonlinear time series,
Factor analysis,
Threshold model,
EM algorithm,
Kalman filter.
</p>

<hr size="1">

    <p>
Texto completo disponible en <a href="pdf/rce/v31n2/v31n2a04.pdf">PDF</a>
</p>

<hr size="1">

    <p>
<b>
<font size="3">
Referencias
</font>
</b>
</p>


    ]]></body>
<body><![CDATA[<!-- ref --><p>
1. Correal, M. E. (2007), Modelo factorial din&aacute;mico con efectos umbral, Tesis doctoral, Departamento de Estad&iacute;stica, Facultad de Ciencias, Universidad Nacional de Colombia.
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2. Forni, M., Hallin, M., Lippi, M. & Reichlin, L. (2005), `The Generalized Dynamic Factor Model: One-Sided Estimation and Forecasting´, <i>Journal of the American Statistical Association</i> <b>100</b>, 830-840.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000024&pid=S0120-1751200800020000400002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
3. Gonzalo, J. & Pitarakis, J. Y. (2002), `Estimation and Model Selection Based Inference in Single and Multiple Threshold Models´, <i>Journal of Econometrics</i> <b>110</b>, 319-352.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000025&pid=S0120-1751200800020000400003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
4. Hansen, B. E. (1997), `Inference in TAR Models´, <i>Studies in Nonlinear Dynamics and Econometrics</i> <b>2</b>, 1-14.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000026&pid=S0120-1751200800020000400004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
5. Hansen, B. E. (2000), `Sample Splitting and Threshold Estimation´, <i>Econometrica</i> <b>68</b>, 575-603.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000027&pid=S0120-1751200800020000400005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
6. Hu, Y. P. & Chou, R. J. (2004), `On the Pe&ntilde;a-Box Model´, <i>Journal of Time Series Analysis</i> <b>25</b>, 811-830.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000028&pid=S0120-1751200800020000400006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
7. Pe&ntilde;a, D. & Box, G. E. P. (1987), `Identifying a Simplifying Structure in Time Series´, <i>Journal of the American Statistical Association</i> <b>82</b>, 836-843.
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8. Pe&ntilde;a, D. & Poncela, P. (2004), `Forecasting with Nonstationary Dynamic Factor Models´, <i>Journal of Econometrics</i> <b>119</b>, 291-321.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000030&pid=S0120-1751200800020000400008&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
9. Pe&ntilde;a, D. & Poncela, P. (2006), `Nonstationary Dynamic Factor Models´, <i>Journal of Statistical Planning and Inference</i> <b>136</b>, 1237-1257.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000031&pid=S0120-1751200800020000400009&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
10. Shumway, R. H. & Stoffer, D. S. (1982), `An Approach to Time Series Smoothing and Forecasting Using the EM Algorithm´, <i>Journal of Time Series Analysis</i> <b>3</b>, 253-264.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000032&pid=S0120-1751200800020000400010&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
11. Stock, J. H. & Watson, M. W. (2002), `Forecasting Using Principal Components From a Large Number of Predictors´, <i>Journal of the American Statistical Association</i> <b>97</b>, 1167-1179.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000033&pid=S0120-1751200800020000400011&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
12. Tsay, R. S. (1989), `Outliers, Level Shifts and Variance Changes in Time Series´, <i>Journal of Forecasting</i> <b>7</b>, 1-20.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000034&pid=S0120-1751200800020000400012&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
13. Tsay, R. S. (1998), `Testing and Modeling Multivariate Threshold Models´, <i>Journal of the American Statistical Association</i> <b>93</b>, 1188-1202.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000035&pid=S0120-1751200800020000400013&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
14. Watson, M. W. & Engle, R. F. (1983), `Alternative Algorithms for the Estimation of Dynamic Factor, Mimic and Varying Coefficient Regression Models´, <i>Journal of Econometrics</i> <b>23</b>, 385-400.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000036&pid=S0120-1751200800020000400014&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p>
15. Wu, L. S., Pai, J. S. & Hosking, J. R. M. (1996), `An Algorithm for Estimating Parameters of State-Space Models´, <i>Statistics & Probability Letters</i> <b>28</b>, 99-106.
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=000037&pid=S0120-1751200800020000400015&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><center>
<b>&#91;Recibido en marzo de 2008. Aceptado en septiembre de 2008&#93;</b>
</center>
<hr size="1">

    <p>
Este art&iacute;culo se puede citar en <i>LaTeX</i> utilizando la siguiente referencia bibliogr&aacute;fica de <i>BibTeX</i>:
</p>
<code><font size="2">@ARTICLE{RCEv31n2a04,    <br>
 &nbsp;&nbsp;&nbsp; AUTHOR &nbsp;= {Correal, Mar&iacute;a Elsa and Pe&ntilde;a, Daniel},    <br>
 &nbsp;&nbsp;&nbsp; TITLE &nbsp; = {{Modelo factorial din&aacute;mico <i>threshold</i>}},    <br>
 &nbsp;&nbsp;&nbsp; JOURNAL = {Revista Colombiana de Estad&iacute;stica},    ]]></body>
<body><![CDATA[<br>
&nbsp;&nbsp;&nbsp; YEAR &nbsp;&nbsp; = {2008},    <br>
&nbsp;&nbsp;&nbsp; volume &nbsp;= {31},    <br>
&nbsp;&nbsp;&nbsp; number &nbsp;= {2},    <br>
&nbsp;&nbsp;&nbsp; pages &nbsp; = {183-192}    <br>
}</font></code>

<hr size="1">
</font>
     ]]></body><back>
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