Full Idea
The original position is the appropriate initial status quo which insures that the fundamental agreements reached in it are fair. This fact yields the name 'justice as fairness'.
Gist of Idea
The original position insures that the agreements reached are fair
Source
Amartya Sen (The Idea of Justice [2009], 01.4)
Book Reference
Sen, Amartya: 'The Idea of Justice' [Penguin 2010], p.17
A Reaction
I suppose it insures fairness on day one of the new society, but that might have all been wiped out in the next fortnight, when you find you are the least advantaged as a result of racism.