Re: st: identifying highest number of consecutive variables where answer is consistent across observation

[Nick Cox <njcoxstata@gmail.com>]

Joe Canner has developed a good strategy for looking at this. Here is another.

Suppose we -reshape long-, something like

gen id = _n
reshape long var, i(id) j(question)
tsset id question

Then we can treat the blocks of observations as panel data. With

ssc inst tsspell
tsspell var

With this syntax for -tsspell- a "spell" is automatically a sequence
of identical values. The existence of spells 15 or longer will be
summarized by

egen fifteen_or_more = total((_seq >= 15) / _end), by(id)

where division by the indicator variable -_end- (1 on end of spell, 0
otherwise) ensures that we look only at the ends of spells. If needed,
we can then -reshape- back.

On the other hand, it is quite likely that some questions of similar
kind are more easily answered with this data structure.

Nick
njcoxstata@gmail.com


On 20 February 2014 17:04, Alison El Ayadi <aelayadi@gmail.com> wrote:

> I am doing some data cleaning on survey data and am looking to
> identify observations where there are 15 or more of the same answers
> in a row (across the variables in current order).  All of the
> variables are string.  Does anyone have an easy automated way to do
> this?  I'm thinking that it could be done by generating a variable
> that provided the maximum number of same responses in a row, but have
> no idea how to code this.  Variables are q1 - q94, and all string.
>
> Any suggestions on efficiently writing this code would be greatly appreciated.
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