Hello,
I have a panel data of firms and the number of units
of products they sell each year. I am trying to
generate some measures of production experience.
One measure I have simply produces a cumulative sum of
the number of products sold up to the previous year:
by id: gen experience1=sum(products[_n-1])
I am now trying to produce more sophisticated measures
that will discount the experience by some given rate
(by, say, dividing the experience by its age). The
idea is that last year's experience is more valuable
than the experience of the year before it and so on.
For example, if I have the following dataset
year 1 - 30 products
year 2 - 20 products
year 3 - 10 products
year 4 - 10 products
year 5 - 20 products
Right now, my experience measure for year 4 is
30+20+10=60. I am looking for a command that will give
me the following value: (30/3)+(20/2)+(10/1)=30
Any idea how can this be done?
Cheers,
Arik Lifschitz
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