difference in combinations

[walid benmouna]

year combination price

2015 1 0.5

2016 1 1

2015 2 2

2016 2 2.5

2015 3 1

2016 3 1.5







Hey guys, i need help creating a new variable in which i need to find the difference in price from 2015 to 2016 for each combination. for example, the first row of the new variable would be (0.5-1) . second would be (2-2.5) and so on..




would really appreciate some help on this

[Nick Cox]

Cross-posted and answered at https://www.reddit.com/r/stata/comme...eed_some_help/

Our policy on cross-posting is explicit. You are asked to tell us about it.

What's more, not only is that spelled out in https://www.statalist.org/forums/help#crossposting -- -- but we flagged in your previous thread https://www.statalist.org/forums/for...a-new-variable that you are asked to read the FAQ (and act on it).

The attitude that I want an answer -- and I don't care if people waste time posting the same answer in different places -- is at least insensitive.