As cities across Africa demand more abundant and affordable food supplies, local officials look for ways to improve systems that have always relied on personal relationships and cultural ties, not formal markets or government regulations. The cities of Sub-Saharan Africa some of the fastest growing in the world face potentially serious dilemmas in supplying their populations with food. Over the past two decades, the continent's agricultural exports have declined while imports have risen sharply. Over the same period, food shortages and increasing prices have spawned strong political protests, notably in heavily urbanized countries such as Cote d'Ivoire and Zambia. Strengthening the connections between consumers in cities and the over 70 percent of Africans who depend on agriculture for their livelihood is considered by many experts to be one of the most important and formidable challenges facing Africa today. In most parts of the continent, the link between farm and marketplace is neither direct or easily understood; distribution systems are frequently obtuse and inefficient, held together by personal relationships, private marketing networks and unregulated transactions.