Reference year inflation rate applied to different years.

[Max Catch]

Hi all,

I am analysing some trial data of respondents who have filled in questionnaires over three separate years. I wish to inflate the data from 2013, 2014, 2015 to the equivalent 2016 dollar amount.

For example someone who filled in a questionnaire on 12/5/2013 i wish to inflate there cost by 2.7%.Eg 100*102.7.
Someone with another date 1/2/2014 i wish to inflate by 2%.

Is there a way i can make stata assign values for dates and then multiply by the relevant inflation amount?

Thanks

[Lance Erickson]

Max,

I think so. But how you'll do it depends on what your data look like. You're likely to get some specific suggestion from the list if you post some example data (see the FAQs).

Lance

[Max Catch]

Hi Lance,

Thanks for getting back to me and apologies about my lack of info in my original post!


----------------------- copy starting from the next line -----------------------

* Example generated by -dataex-. To install: ssc install dataex
clear
input int participantid float(date cost)
212 19505 239.61
616 19585      6
185 19298  574.8
344 19646  23.58
707 19667   36.1
812 19416  77.39
144 19243 188.54
259 19260 111.84
267 19292  29.71
end
format %d date

------------------ copy up to and including the previous line ------------------

Listed 9 out of 9 observations

I wish to multiple cost by the percentage listed within the table below.

2013	2014	2015	2016
94.1	95.7	98	100

Does it just mean some big coding specifying to multiple if within range or is there an easier way?

Any help would be great.

Thanks again

Max

[Lance Erickson]

There are, I'm sure, any number of ways to do it. Here's one possibility...

generate year = year(date)

recode year (2012=.93)(2013=.941)(2014=.957)(2015=.98)(2016=1), gen(mult)
gen adjusted = cost*mult

I assumed the date variable was a Stata date (i.e., days since 01jan1960). Under that scenario, there were observations from 2012 and 2013 so I made up a cost adjustment for 2012.

Lance

[Max Catch]

Thank you so much for your assistance lance! Will work on my questioning technique in future posts!

[Nick Cox]

Another possibility is to use a Stata matrix as a look-up table: Using a year variable as shown by Lance,

matrix factor = (.93, .941, .957, .98, 1)'  matrix list factor  gen adjusted = cost * factor[year - 2011, 1]

See also http://www.stata-journal.com/sjpdf.h...iclenum=pr0054

[Nick Cox]

Sorry for poor formatting:

matrix factor = (.93, .941, .957, .98, 1)'  
matrix list factor  
gen adjusted = cost * factor[year - 2011, 1]