How do I create a dummy variable for years?

[bazargur]

Hello,

I want to create a dummy variable for a regulatory policy called MSA.

For my model I have a sample size from years 1970-2014. 

If any years <1998 then MSA=0 and anything above 1998 MSA=1

If anyone can help me with the coding on this, I would really appreciate it.

Thank you all.

[Reeza]

Standard if/then?

If year<1998 then MSA=0;
Else if year >=1998 then MSA=1;