Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Creating Dummys from a variable with 5 categories


From   daniel klein <klein.daniel.81@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Creating Dummys from a variable with 5 categories
Date   Sun, 2 Dec 2012 11:41:44 +0100

Sharon,

reading this once again, I might have got you wrong. Do you want _one_
dummy (indicator) variable, indication anything else but "flat fee"?
If so, read on. If not, ignore the rest of this message.

In this case you (probably) want the indicator to be 1 if a person
checks anything but "flat fee", 0 otherwise, making "flat fee" your
reference in follwoing analysis. The code you gave is basically ok
(besides not handling missing values, see below), it merely reverses
this coding. It assigns 1 if the answer is "flat fee", 0 otherwise.
Note that the coding order (i.e. 1 for "flat fee" vs. 0 for "flat
fee") does not really matter, as it merely changes the sign of an
estimated coefficient. But if want "flat fee" to be the reference,
code instead

g byte not_flatfee = (YYYY != 1) if !mi(YYYY)

Note the -if- qualifier, to make sure missing values in YYYY are also
missing values in the created dummy variable. Omitting the -if-
qualifier results in missing values in YYYY being coded 1 in the
indicator variable.

I am not sure what you mean by your code not incorporating  "all the
variables" -- there is only one variable (i.e. YYYY) with 5 levels
(i.e. distinct values).

Best
Daniel
-- 
[...]

I have a variable with 5 answers and need to make a dummy variable from it

[...]

If I want to create a dummy variable that uses Flat Fee as a reference point

[...]
*
*   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/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index