Ben Dulong wrote:
Consider the variables:
y=0 or y=1
x1=0 or x1=1
x2=0 or x2=1
x3=0 or x3=1
xtotal = x1+x2+x3
xtotal is a scale calculated from the items x1,x2,x3.
Which is the better syntax?
logistic y xtotal
or
xi: logistic y i.xtotal
The answer: It depends!
Is it theoretically meaningful to summarize the x variables? Do they
together form an additive scale/dimension?
Are the x's highly correlated? The more yes'es to these questions, the
more likely the first syntax is the better? However, the last syntax will
(here) also test whether there is a linear relationship between Y and
xtotal.
Best regards,
Christer
Christer Thrane, dr. polit.
Associate Professor, Sociology
Faculty of Tourism and Applied Social Science
Lillehammer College
Gudbrandsdalsv. 350
2626 Lillehammer, Norway
+ 47 61 28 81 70 (fax)
+ 47 61 28 82 47 (phone, work)
+ 47 61 25 68 44 (phone, home)
+ 47 92 29 54 39 (mobile)
E-mail, work: [email protected]
E-mail, home: [email protected]
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