What part of the world is bustling? Africa

The shops are stacked six feet high with goods; the streets outside are jammed with customers, and salespeople are sweating profusely under the onslaught.

But this is not a high street during the Christmas-shopping season in the rich world. It is the Onitsha market in southern Nigeria, every day of the year.

Many call it the world's biggest. Up to 3 million people go there daily to buy rice and soap, computers and construction equipment.

It is a hub for traders from the Gulf of Guinea, a region blighted by corruption, piracy, poverty and disease but also home to millions of highly motivated entrepreneurs and increasingly prosperous consumers.

Over the past decade, six of the world's 10 fastest-growing countries were African. In eight of the past 10 years, Africa has grown faster than East Asia, including Japan.

Africa is expected to grow by 6 percent this year and nearly 6 percent in 2012, about the same as Asia.

The commodities boom is partly responsible. In 2000-08, around a quarter of Africa's growth came from higher revenues from natural resources. Favorable demography is another cause.

Optimism about Africa needs to be taken in fairly small doses, for things are still exceedingly bleak in much of the continent.

Most Africans live on less than $2 a day. The average life span in some countries is less than 50. Drought and famine persist. The climate is worsening.

Some countries praised for their breakneck economic growth, such as Angola and Equatorial Guinea, are oil-sodden kleptocracies. Some that have begun to get economic development right, such as Rwanda and Ethiopia, have become politically noxious.

Congo still looks barely governable and hideously corrupt. Zimbabwe is a scar on the conscience of the rest of southern Africa. South Africa, which used to be a model for the continent, is tainted with corruption.

Yet against that depressingly familiar backdrop, some fundamental numbers are moving in the right direction. Africa now has a fast-growing middle class. The rate of foreign investment has soared around tenfold in the past decade.

The health of many millions of Africans has also improved, thanks in part to the wider distribution of mosquito nets and the gradual easing of the ravages of HIV/AIDS. Skills are improving: productivity is growing by nearly 3 percent a year, compared with 2.3 percent in America.

All this is happening partly because Africa is at last getting a taste of peace and decent government.

For three decades after African countries threw off their colonial shackles, not a single one (bar the Indian Ocean island of Mauritius) peacefully ousted a government or president at the ballot box.

But since Benin set the mainland trend in 1991, it has happened more than 30 times--far more often than in the Arab world.

Population trends could enhance these promising developments. A bulge of better-educated young people of working age is entering the job market, and birth rates are beginning to decline.

Having a lot of young adults is good for any country if its economy is thriving, but if jobs are in short supply it can lead to frustration and violence. Whether Africa's demography brings a dividend or disaster is largely up to its governments.

Africa still needs deep reform. Governments should make it easier to start businesses. Land needs to be taken out of communal ownership and titles handed over to individual farmers so that they can get credit and expand.

And, most of all, politicians need to keep their noses out of the trough and to leave power when their voters tell them to.

Western governments should open up to trade rather than just dishing out aid. African governments should insist on total openness in the deals they strike with foreign companies and governments.