But you don't need complicated calculations to see what's happening in the horn of Africa. I've seen famine in the vacant eyes of mothers who watched helplessly as their children died, and in the distended bellies of babies who were still alive, but not for long.
This is the first official famine in East Africa in 19 years. But an alternating current of drought, famine and war has plagued this land and its mostly innocent people for all of human history.
Drought is inevitable in the arid regions of East Africa. Famine follows, killing thousands who never recover enough from the last famine to fend off the ravages of the next.
So, what are we to do about a tragedy that recurs and persists despite heroic efforts of a world community that shakes off its compassion fatigue every few years to save the lives of strangers?
How much more pointless and futile does the effort seem when armed bandits block the flow of humanitarian aid, demanding tributes from agencies and individuals who work to break this cycle of death?
In '92, the United Somali Congress and the Somali People's Movement combined to drive dictator Mohamed Siad Barre out of power. Then they turned on each other and in the process stymied all aid efforts. The U.S. had shipped 80,000 metric tons of dry-food aid by October '91. Nine months later, it still sat in packing crates in Mombasa, Kenya.
Finally, on Aug. 31, 1992, whichever warlord held check at the time allowed a U.S. C-130 to airlift 12 tons of relief supplies to a dirt airstrip in Belet Uen province. But not until the U.S. had met his terms of engagement.
I watched in amazement the night before as U.S. airmen painted over every U.S insignia on that cargo plane in compliance with that warlord's order. A Marine brigadier general named Frank Libutti and his men went in unarmed, and only the 23 reporters on board were allowed to get off the plane.
This time the checkholder is al-Shabaab, an al Qaeda affiliate that controls south-central Somalia, where the famine is centered. After months of negotiations, it is finally allowing aid agencies to airlift supplies to the affected area.
Secretary of State Hillary Clinton announced Wednesday that $28 million in additional U.S. aid is headed for the region. She said she is "cautiously optimistic that al-Shabaab will permit unimpeded international assitance."
If so, this aid infusion would augment some $430 million in U.S. aid that has gone into the region this year, including $50 million to Somalia alone.
But it's not enough. Mark Bowden, a U.N. official coordinating relief aid to Somalia, said that it will take an additional $300 million to break the cycle in Somalia, Sudan, Djibouti and Kenya.
Alexis Moore Bruton, a spokeswoman for the American Friends Service Committee, at 15th and Cherry streets, said that its representative should be "on the ground in Somalia" by today.
"There are 3.7 million people in this food crisis," Bruton said. "It's the worst drought in 60 years, and it's complicated by soaring food prices and the conflicts.
"But we issued an appeal on July 8, and we'll take anything that people want to give."
AFSC can be reached by phone at 1-888-588-2372. Interaction.org offers a number of other ways to make donations. So does the American Red Cross.
Send email to email@example.com or call 215-854-2512. For recent columns: www.philly.com/ElmerSmith.