Nigeria has emerged as Africa’s largest economy, with 2014 GDP estimated at US$479 billion. Oil has been a dominant source of government revenues since the 1970s. While regulatory constraints and security risks have limited new investment in oil and natural gas, the Nigerian economy has continued to grow at a rapid 6% to 8% per annum (pre-rebasing), driven by growth in agriculture, telecoms and services. The medium-term outlook for Nigeria is good, assuming oil output stabilises and oil prices remain strong.