Perhaps I can add to that.
The sense one gets from the Professor Sarlo approach--he stressed this in his conclusion--is that we shouldn't take any steps before we've agreed on statistical methodologies and so on.
The effect of this would be to induce a kind of paralysis: “Oh, this is complicated. Oh, this is controversial. Hmm, we can't do anything until we've figured out how to do it.” Meanwhile, people are homeless. People are living in hunger. Those are the realities, in this paralysis-inducing approach, that Professor Sarlo begs us to hold off on.
The second thing is that we're talking about fundamental human rights--fundamental, worldwide, shared human rights. Do we ask ourselves how we can minimally avoid those, how we can prevent ourselves from engaging and respecting them? The Prime Minister was abroad recently saying that human rights are so important and we have to live up to them and fully respect them. That won't happen if we sit around asking how we measure it. We look at the realities of poverty and say that people have a right to dignity and a right to an adequate income.