Most NGOs and all the unions in Colombia take the data from the ENS as the formal source, and that's what we do also. We could have taken the data from the government to do all the exercises, but then the question is, is the data reported by the government correctly? So in order to bullet-proof the paper, we take the data from the unions and test the claims and test the evolution, etc.
On November 24th, 2009. See this statement in context.