I need help with merging two datasets under multiple conditions

[Kemi Balogun]

the first dataset has project id, country, start year, end year and the other has country, institution variable over a range of years
I want to merge the first with the second such that it shows project id, country, and average institituion value between the start and end date.
I have tried using merge but it's not working.

[William Lisowski]

Your question really isn't clear without more detail, or at a minimum it is too difficult to guess at a good answer from what you have shared. Please help us help you. Show example data for your two datasets. Show your merge code. Show us what Stata told you. Tell us what precisely is wrong. The Statalist FAQ provides advice on effectively posing your questions, posting data, and sharing Stata output.