<?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>0121-4772</journal-id>
<journal-title><![CDATA[Cuadernos de Economía]]></journal-title>
<abbrev-journal-title><![CDATA[Cuad. Econ.]]></abbrev-journal-title>
<issn>0121-4772</issn>
<publisher>
<publisher-name><![CDATA[Universidad Nacional de Colombia]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0121-47722023000200359</article-id>
<article-id pub-id-type="doi">10.15446/cuad.econ.v42n89.97316</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Not all Giffen goods, are inferior goods.]]></article-title>
<article-title xml:lang="es"><![CDATA[No todos los bienes Giffen, son bienes inferiores.]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Vallejo]]></surname>
<given-names><![CDATA[Hernán]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad de los Andes Facultad de Economía ]]></institution>
<addr-line><![CDATA[Bogotá ]]></addr-line>
<country>Colombia</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2023</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2023</year>
</pub-date>
<volume>42</volume>
<numero>89</numero>
<fpage>359</fpage>
<lpage>378</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_arttext&amp;pid=S0121-47722023000200359&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_abstract&amp;pid=S0121-47722023000200359&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.co/scielo.php?script=sci_pdf&amp;pid=S0121-47722023000200359&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[ABSTRACT It is well known in the economic literature that the labour supply curve can bend backwards and, therefore, that leisure can be a Giffen good. It is also known that leisure can be a normal good. This article proves that if leisure is a Giffen good, it has to be a normal good. This result also proves that, contrary to common knowledge in economics, not all Giffen goods, are inferior goods. These results could be taken into account, for example, when finding empirical evidence and designing policies on labour supply, in an era of machine learning and artificial intelligence.  JEL: D01, D04, D11, J22, J38.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[RESUMEN Es bien sabido en la literatura económica que la curva de oferta de trabajo puede tener pendiente negativa y, por tanto, que el ocio puede ser un bien Giffen. También se sabe que el ocio puede ser un bien normal. Este artículo demuestra que si el ocio es un bien Giffen, tiene que ser un bien normal. Este resultado también prueba que, contrario a la creencia popular en la economía, no todos los bienes Giffen, son bienes inferiores. Estos resultados podrían ser útiles por ejemplo, a la hora de encontrar evidencia empírica y diseñar políticas sobre oferta laboral, en una era de aprendizaje automático e inteligencia artificial.  JEL: D01, D04, D11, J22, J38.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Leisure]]></kwd>
<kwd lng="en"><![CDATA[Giffen goods]]></kwd>
<kwd lng="en"><![CDATA[excess expenditure function]]></kwd>
<kwd lng="en"><![CDATA[Shephard's lemma]]></kwd>
<kwd lng="es"><![CDATA[ocio]]></kwd>
<kwd lng="es"><![CDATA[bienes Giffen]]></kwd>
<kwd lng="es"><![CDATA[función de exceso de gasto]]></kwd>
<kwd lng="es"><![CDATA[lema de Shephard]]></kwd>
</kwd-group>
</article-meta>
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