A new study from Commerzbank finds that after a long period of post-crisis sustained economic growth and resilience, Sub-Saharan African economies are now being negatively affected by a high dependence on raw material exports.

The study notes that, in the wake of the commodity-price downturn, “the first hard-hit countries were Africa’s largest oil producers, such as Nigeria and Angola,” and suggests that “growing economic imbalances, withdrawal of capital by international investors, and the absence of structural reform and diversification efforts” pose severe implications for countries across the region.

The study, titled “Sub-Saharan Africa: Tackling the headwinds after the economic turnaround,” offers a macroeconomic outlook for the region, explores targeted case studies for selected countries, and sets out a growth agenda for the future of Africa’s foreign trade, industry, agriculture, labor and finance markets.

“Every cloud has a silver lining,” commented Christian Toben,  Commerzbank’s regional head of Africa. “We are closely observing how individual countries of the region—from Angola to Zambia—are tackling these challenges and taking their chance to strengthen their market performance.”

Despite Nigeria’s increasing challenges, the continent’s largest economy still holds the keys to growth, according to the report. The country’s success will depend on a “rapid fiscal adjustment and diversification of its economy to reduce the government’s dependence on oil revenues.”

Elsewhere, an economy making particular headway is Ivory Coast, which has grown by eight to ten percent since 2012, “driven by reforms in the agricultural sector, brisk transportation and construction activities as well improved private-sector investment”, all helped by political stability in the country. On the other side of the continent, Tanzania’s service sector has spurred solid growth of “around seven percent of GDP over the last five years”.

Commerzbank has 60 years of experience in the Sub-Saharan African region. The bank has representative offices in Lagos, Nigeria, Addis Ababa, Ethiopia, Johannesburg, South Africa, Luanda, Angola, and Cairo, Egypt. The bank’s new representative office in Abidjan, Ivory Coast, opened in 2015.