duplicates tag in a foreach loop

[Linda Pasi]

Hello everyone.

I am trying to make this loop run but it keeps on giving me { required r(100). I am doing an event study on M&As.

Does someone know what I am doing wrong?

adate_and_cusip is a concat of date of announcement (of the deal) and cusip is my company id.

I need to know how many deals each company made over 3 years around date(year) of announcement.

local adateandcusip `adate_and_cusip'
version 7
 foreach i of `adateandcuisp'{
 forval year=1990(3)2011 {
 duplicates tag DateAnnounced `i', gen(frequencydeals`i')
 }
 }