Here's a little quiz: What do Liberia, Yemen and Haiti have in common?
If you said "food riots,'' you would be right. People in all three countries have recently rioted over the soaring cost of rice, a dietary staple through much of the world.
And here's another dubious distinction those countries share: birth rates and population growth rates that are far higher than average.
Take Liberia, whose 3.4-million people are among the world's poorest. The war-ravaged African nation ranks No. 1 in population growth, with Liberians reproducing at such a fast clip the population will double in just 18 years. Liberia ranks third in actual births per 1,000 people — nearly 50, compared to 20 worldwide and just eight in thriving Singapore.
Yes, there's a striking correlation between countries where people are rioting over food and countries where the population is exploding. And unbridled population growth will pose one of the greatest security challenges this century, CIA Director Michael Hayden told students at Kansas State University last week.
"Most of that growth will occur in countries least able to sustain it, a situation that will likely fuel instability and extremism, both in those countries and beyond," Hayden warned.
Controlling population has always been a sticky topic because it is so often laden with religious, political and ideological overtones. At its horrific worst, it can be a tool of genocide and ethnic cleansing, as with the sterilization of Jews in Nazi Germany.
Conversely, high birth rates are sometimes seen as a desirable way of gaining demographic advantage. Many Palestinians, whose population is among the world's fastest-growing, hope to overtake Jews as the dominant people between the Jordan River and the Mediterranean Sea by 2020. But the population explosion has come at a heavy cost: most of the 1.5-million Palestinians in the narrow Gaza Strip are poor and heavily dependent on U.N. food aid.
While it is hard to discuss population control dispassionately, there's certainly evidence that it can have positive results. Consider Thailand and the Philippines.
In 1974, the Thai government began an aggressive birth control policy that included vasectomy clinics and free condoms. Now, Thailand, the world's biggest rice exporter, has a low population growth rate, a robust economy — and no food riots among its 65-million people.
The population of the Philippines, by comparison, is 93-million and growing at a rate far above average. Though 90 percent of Filipinos say the government should provide free birth control for the poor, the strong influence of the Catholic church has kept that from happening. The Philippines is now the world's biggest rice importer and is among the nations most at risk of unrest as rice prices soar, experts say.
Few population control measures have been criticized more than China's often brutally enforced "one child'' policy. Yet China, whose 1.3-billion people make it the world's most populous country, has also seen a dramatic reduction in poverty and the rise of a substantial middle class.
But wait — that's not necessarily all good. As the middle classes swell in places like China and India, they tend to favor beef and other high-protein foods over plain old rice. That drives up the prices of wheat, corn and other grains needed to fatten all those cows, hogs or chickens for the dinner table.
"The problem is not the basic birth rate in most parts of the world — it is the rise in the percent of the population that is middle class that is increasing the pressure on purchasing,'' says Laurie Garrett, senior fellow at the Council on Foreign Relations.
Still, with 6.7-billion of us on a stressed planet — and 2.5-billion more expected in another 40 years — it seems smart to consider what Dr. Martin Luther King Jr. once said about overpopulation:
"What is lacking … is universal consciousness of the gravity of the problem and education of the billions who are its victim."
Susan Taylor Martin can be reached at email@example.com.