(CNN)The performance of some of Africa's largest economies in 2018 does not inspire confidence for the year ahead.
Nigeria has endured a slow recovery from a recession caused by falling oil prices, as has Angola. South Africa entered recession for the first time in a decade.
But away from the flagship economies, emerging powers and international trends offer the prospect of new success stories.
Global management consultancy McKinsey & Company's new book "Africa's Business Revolution" identifies areas of potential progress and opportunity across the continent based on original research and interviews with hundreds of CEOs from leading African companies. The authors find regions that recall China before its own period of explosive growth, and suggest pathways that could yield similar gains.
Rapid urbanization will greatly expand the consumer class with disposable incomes, the authors predict, which will lead to a massive increase in business and consumer spending -- rising from $4 trillion in 2015 to $5.6 trillion in 2025. In the same period, increased Internet penetration will add $300 billion to the continent's GDP -- roughly equivalent to South Africa's output.
With the help of Acha Leke, co-author of "Africa's Business Revolution" and chairman of McKinsey's Africa office, we pick out some of the major trends and stories to watch in Africa in 2019 and beyond.
The ascendent middle powers
When McKinsey surveyed the top 30 African economies in 2011, they found 25 were experiencing "accelerated growth." In the most recent survey of the same countries, the figure was just 13. Rather than the continental powerhouses, it is the mid-sized economies such as Ethiopia and Ivory Coast that offer the greatest promise.
Leke picks out Ivory Coast as a model of stable progress, having recorded steady growth since emerging from a civil war and financial crisis around the turn of the decade. He cites high levels of government investment and infrastructure development in partnership with Chinese firms as key factors in the country's performance, and suggests that "huge investor interest" from the private sector can keep the economy buoyant. The coming years should see growth become more inclusive with progress in sectors such as health and education.
A closer union
While the European Union is under strain from resurgent nationalism within member states, African countries are choosing closer alignment. The Continental Free Trade Area (CFTA) will create one of the world's largest free trade blocs, with 44 countries now signed up. Of the major economies, only Nigeria has abstained, and Leke believes that position is likely to change in the near future.