How can they know that?

As I've had occasion to mention before, I'm on the e-mail list of the ONE campaign.

The following message from ONE arrived in my in-box today:

Dear ___,

Budget battles are never easy - except when there's a clear choice to save lives.

Right now, the House is proposing 18% cuts to global agriculture and economic development programs in next year’s budget. They’re proposing 9% cuts to global health programs.

And the Senate? No cuts at all - and in some cases even small increases.

It’s time to tell the House to think again.

…
It’s easy to just throw around numbers, but what would these House budget cuts really mean for the world’s poorest people? Nearly 50,000 children will not receive treatment for malaria. 900,000 children won’t receive nutrition interventions. 1.1 million children won’t be immunized. 1.9 million people won’t be able to escape extreme poverty.

We’ve got to let Congress know that the Senate bill is the only way to go. So today, we’re joining with our partners - Bread for the World, CARE, Oxfam, RESULTS, Save the Children - and making as many phone calls as we can to Capitol Hill.

I agree with ONE on the legislative issue here, but the sentence "1.9 million people won't be able to escape extreme poverty" is odd. You don't have to know a whole lot about development programs to know that it's extremely difficult to estimate, even to this kind of rounded figure, how many people will or won't escape extreme poverty as a result of a particular level of funding for certain programs. ONE's cause, which I support, is not well served by this.