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Logit, Probit and Tobit: Models for Categorical and Limited ...

Logit, Probit and Tobit: Models for Categorical and Limited ...

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The <strong>Logit</strong> <strong>and</strong> <strong>Probit</strong> <strong>Models</strong><br />

• However However, the parameters of the two models are<br />

scaled differently. The parameter estimates in a<br />

logistic g regression g tend to be 1.6 to 1.8 times higher g<br />

than they are in a corresponding probit model.<br />

• The probit p <strong>and</strong> logit g models are estimated by y<br />

maximum likelihood (ML), assuming independence<br />

across observations. The ML estimator of β is<br />

consistent i <strong>and</strong> dasymptotically i ll normally ll distributed. di ib d<br />

However, the estimation rests on the strong<br />

assumption that the latent error term is normally<br />

distributed <strong>and</strong> homoscedastic. If homoscedasticity is<br />

violated, , no easy ysolution.

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