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Dummy Variable Regression

Indicator regression, many times, employs both quantitative and qualitative X, variables. For example, if one wished to measure the microorganisms normally found on the skin of men and women, relative to their age, the following regression model might be used [Pg.341]

This model is composed of two linear regressions, one for males and the other for females. [Pg.341]

The plotted regression functions would be parallel—same slopes, but different y-intercepts. Neither 0 nor 1 is the required representative value to use— any will do—but they are the simplest to use. [Pg.342]

In general, if there are c levels of a specific quantitative variable, they must be expressed in terms of c — 1 levels to avoid collinearity. For example, suppose multiple anatomical sites, such as the abdominal, forearm, subclavian, and inguinal, are to be evaluated in an antimicrobial evaluation. There are c = 4 sites, so there will be c—1 = 4—1 = 3 dummy x variables. The model can be written as [Pg.342]

When Xl =X2=X3 = 0, the model represents the inguinal region. Let us write out the equations to better comprehend what is happening. The full model is [Pg.342]


Data on the number of incidents of damage to a sample of ships, with the type of ship and the period when it was constructed, are given in Table 7.8 below There are five types of ships and four different periods of construction. Use F tests and dummy variable regressions to test the hypothesis that there is no significant ship type effect in the expected number of incidents. Now, use the same procedure to test whether there is a significant period effect. ... [Pg.28]

When using dummy variable regression, one can directly compare the two or more regression lines. There are three basic questions ... [Pg.353]


See other pages where Dummy Variable Regression is mentioned: [Pg.341]    [Pg.341]    [Pg.343]    [Pg.345]    [Pg.347]    [Pg.349]    [Pg.351]    [Pg.353]    [Pg.355]    [Pg.357]    [Pg.359]    [Pg.361]    [Pg.363]    [Pg.365]    [Pg.367]    [Pg.369]    [Pg.371]    [Pg.373]    [Pg.375]    [Pg.377]    [Pg.379]    [Pg.381]    [Pg.383]    [Pg.385]    [Pg.387]    [Pg.389]    [Pg.391]    [Pg.395]    [Pg.397]    [Pg.399]    [Pg.401]    [Pg.403]    [Pg.405]    [Pg.407]   


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Dummy variables variable

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