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From |
Richard Williams <[email protected]> |

To |
[email protected], <[email protected]> |

Subject |
Re: st: Re: Ordinal independent variables in probit regression |

Date |
Wed, 09 Apr 2014 23:09:32 -0500 |

You could do something like this: webuse nhanes2f, clear probit diabetes i.health est store m1 probit diabetes health est store m2 lrtest m1 m2 If the contrast is not significant you can treat the variable as continuous.

At 07:15 PM 4/9/2014, Joseph Coveney wrote:

Nyasha Tirivayi wrote: How best can I use a likert scale/ordered predictor in a probit regression? The variable has five response categories from Strongly disagree to Agree (neutral is the third response option). Should I include the variable as it is, where one category becomes the reference? Or should I consider the variable to be continuous? Or should I instead use the tab command to create dummies for all five response options, and include the ones I am interested in ( e.g. strongly agree and agree responsea)? -------------------------------------------------------------------------------- There are numerous ways to include it as a predictor. You could use factor variables and then use -contrast- after fitting the model. You could put the scores in linearly (as a continuous predictor). But it seems that you've already hit upon the way that makes most sense from the standpoint of how best to address the question of scientific interest: create three indicator variables, one for strongly agree, one for agree, and one for all of the other scores--something like that below. (You can accomplish the same thing using a factor variable and then constructing particular contrasts of interest after fitting the model.) generate byte strongly_agree = likertlike_score == "Strongly Agree" generate byte agree = likertlike_score == "Agree" generate byte others = !strongly_agree & !agree probit response c.(strongly_agree agree others) Joseph Coveney * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

------------------------------------------- Richard Williams, Notre Dame Dept of Sociology OFFICE: (574)631-6668, (574)631-6463 HOME: (574)289-5227 EMAIL: [email protected] WWW: http://www.nd.edu/~rwilliam * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: Re: Ordinal independent variables in probit regression***From:*Nyasha Tirivayi <[email protected]>

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