I have a dataframe of about 3 000 acquisition bids.

Variables:
  • Company ID (PERMNO)
  • Bid ID (ID)
  • Announcement date (ANDATE)
  • Bidding round (ROUND_ID)
Array
Bids are in competition with each other and grouped by ROUND_ID.

Problem:
I would like to write a code that runs through each ROUND_ID and saves the first observation (by ANDATE) in a separate dataframe. I.e. I would like to subset the first bid of each bidding round, and then create a different subset with the follower-bids.

Can anyone help me with this?