LAGOS, Nigeria - In a quarter century, at the rate Nigeria is growing, 300 million people - a population about as big as that of the United States - will live in a country the size of Arizona and New Mexico. In this commercial hub, where the population has by some estimates nearly doubled over 15 years to 21 million, living standards for many are falling.
Lifelong residents like Peju Taofika and her three granddaughters inhabit a room in a typical apartment block known as a “Face Me, Face You’’ because whole families squeeze into 7-by-11-foot rooms along a narrow corridor. Up to 50 people share a kitchen, toilet, and sink - though the pipes in the neighborhood often no longer carry water.
At Alapere Primary School, more than 100 students cram into most classrooms, two to a desk.
As graduates pour out of high schools and universities, Nigeria’s unemployment rate is nearly 50 percent for people ages 15 to 24 in urban areas - driving crime and discontent.
The growing upper-middle class also feels the squeeze, as commutes from even nearby suburbs can run two to three hours.
Last October, the United Nations said the global population had breached 7 billion and would expand for decades, taxing natural resources if countries cannot better manage the growth.
But nearly all of the increase is in sub-Saharan Africa, where the rise in population outstrips economic expansion. Of the roughly 20 countries where women average more than five children, almost all are in the region.
Elsewhere in the developing world, in Asia and Latin America, fertility rates have fallen sharply in recent generations and now resemble those in the United States - just above two children per woman. That transformation was driven in each country by a mix of educational and employment opportunities for women, access to contraception, urbanization, and an evolving middle class. Whether similar forces will defuse the problem in sub-Sarahan Africa is unclear.
“The pace of growth in Africa is unlike anything else ever in history and a critical problem,’’ said Joel E. Cohen, a professor of population at Rockefeller University in New York City. “What is effective in the context of these countries may not be what worked in Latin America or Kerala or Bangladesh.’’
Across sub-Saharan Africa, governments have begun to act, often reversing policies that encouraged large families. Nigeria made contraceptives free last year, and officials are promoting smaller families as a key to economic salvation.
Nigeria, already the world’s sixth most populous nation with 167 million people, is a crucial test case, since its success or failure at bringing down birthrates will have outsize influence on the world’s population. If this nation rich with oil cannot control its growth, what hope is there for many smaller, poorer countries?
“Population is key,’’ said Peter Ogunjuyigbe, a demographer at Obafemi Awolowo University in the city of Ile-Ife. “If you don’t take care of population, schools can’t cope, hospitals can’t cope, there’s not enough housing - there’s nothing you can do to have economic development.’’
The government is building infrastructure but cannot keep up, and some analysts worry that it, and other African nations, will not act forcefully enough to rein in population growth. For two decades, the Nigerian government has recommended that families limit themselves to four children, with little effect.
Although he acknowledged that more countries were trying to control population, Parfait M. Eloundou-Enyegue, a professor of development sociology at Cornell University, said “many countries only get religion when faced with food riots or being told they have the highest fertility rate in the world or start worrying about political unrest.’’
In Nigeria, analysts say, the swelling ranks of unemployed youths with little hope has fed the growth of the radical Islamist group Boko Haram.
Globally, the African population boom means more illegal immigration, according to Frontex, the European border agency.
Nigeria has experienced a slight decline in average fertility rates, to about 5.5 last year from 6.8 in 1975. But this level, combined with a young population, still puts such countries on a steep growth curve.