st: Creating a time lag dummy

[Martijn S <martstouthart@gmail.com>]

Hello,

I have a problem generating a ‘special’ dummy. This is my problem. I
have the following columns fyear and year_ipo. Now I want to create a
dummy which gives a 1 when a company has gone public in the prior 5
calendar years and a 0 otherwise.

So for example, I have a company which had an IPO in 1999. So this
dummy should create a 1 for the fiscal year 2000,2001…,2004 and a zero
for 2005,2006…2010.

Unfortunately I cannot get the dummy working.

I hope that someone can help me solving my problem.

Thanks,

Martijn

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