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From |
Shikha Sinha <shikha.sinha414@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: cascading dummies |

Date |
Mon, 1 Oct 2012 13:07:00 -0700 |

Thanks! Shikha On Mon, Oct 1, 2012 at 12:15 PM, Nick Cox <njcoxstata@gmail.com> wrote: > As Richard said, Stata can tell you: > > . findit cascade > > STB-6 srd11 . . . . . . . . . Generating ordered "cascading" dummy variables > (help cascade if installed) . . . . . . . . . . . . . . . R. Goldstein > 3/92 pp.19--22; STB Reprints Vol 1, pp.190--194 > add a set of new dummy variables that are cascading; that is, > 0/1 variables are created where a 1 is given if the case has > the value <= value of lowest category > > Accessible at http://www.stata.com/products/stb/journals/stb6.pdf > > Nick > > On Mon, Oct 1, 2012 at 7:59 PM, Shikha Sinha <shikha.sinha414@gmail.com> wrote: >> Thanks Richard! >> >> very helpful. What is the full reference of STB article, I am unable to find it. > > On Mon, Oct 1, 2012 at 11:39 AM, Richard Goldstein >> <richgold@ix.netcom.com> wrote: > >>> neither is wrong or right -- they answer slightly different questions; A >>> asks for each dummy whether, and by how, much it is different from the >>> reference group (you do realize that you should only include 4 of the >>> dummies, right?); B asks whether each differs from the preceding level >>> >>> you can -findit cascade- to find a program I wrote to implement >>> cascading dummies; the help file, and even more the STB article, >>> discusses the differences; note that you can obtain the answer to either >>> question by following up the original method of forming the variables >>> with the appropriate -test- command(s) > > On 10/1/12 2:31 PM, Shikha Sinha wrote: > >>>> Recently, I came across a new way of creating dummies and I wonder >>>> what the group thinks about this form. >>>> >>>> The independent variable X is coded as 1- very poor, and 5 as very >>>> rich. I want to estimate the effect by wealth quintile. I created the >>>> dummy the following ways, but I was told that this is wrong (A is >>>> wrong). The correct way to construct dummy is B and is called >>>> cascading dummies. I have never come across this before and would >>>> appreciate if you could shed light on the difference between the two >>>> and which is the correct way of creating dummies. >>>> >>>> A: >>>> id Y X1 (scale of 1-5), dum1 dum2 dum3 dum4 dum5 >>>> 1 100 5 0 0 0 0 1 >>>> 2 200 4 0 0 0 1 0 >>>> 3 300 3 0 0 1 0 0 >>>> 4 239 2 0 1 0 0 0 >>>> 5 345 1 1 0 0 0 0 >>>> >>>> >>>> B: >>>> id Y X1 (scale of 1-5), dum1 dum2 dum3 dum4 dum5 >>>> 1 100 5 1 1 1 1 1 >>>> 2 200 4 1 1 1 1 0 >>>> 3 300 3 1 1 1 0 0 >>>> 4 239 2 1 1 0 0 0 >>>> 5 345 1 1 0 0 0 0 > * > * 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/ * * 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/

**References**:**st: cascading dummies***From:*Shikha Sinha <shikha.sinha414@gmail.com>

**Re: st: cascading dummies***From:*Richard Goldstein <richgold@ix.netcom.com>

**Re: st: cascading dummies***From:*Shikha Sinha <shikha.sinha414@gmail.com>

**Re: st: cascading dummies***From:*Nick Cox <njcoxstata@gmail.com>

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