Hi Stata Forum,

I have a rather basic question on dropping observation that I cannot seems to solve. I'm working on analyzing word construct of CEOs letter in many companies for 10 years. But some year have two or more different CEO observation and I would like to keep only the last one. Here an example of my data:
Ticker Symbol Year Name JobTitle relative_prom relative_prev
ABBA 2008 Jerry Yang Chief Executive Officer, Director 1712 2.336449
ABAA 2008 Steve Ballmer CEO 330 0
ABBA 2009 Carol Bartz CEO 2584 105
ABBA 2010 Carol Bartz Chief Executive Officer 1082 .9242144
ABBA 2011 Carol Bartz Chief Executive Officer, President and Director 4950 2.121212
AABA 2011 Timothy R. Morse Interim Chief Executive Officer, Chief Financial Officer 4429 2.370738
ABBA 2011 Marissa A. Mayer CEO 10402 2.595655
So, for example, I just want to keep only Steve Ballmer for 2008 observation and only Marissa Mayer for 2011. This also happens in most of the companies and I don't know the exact command I should use in order to do that.
Thank you!