How African Agriculture is under-rated due to narrow notions of evidence

When economists and policy makers in developing countries talk about evidence, in most cases they mean numbers or statistics. For instance in African countries, statistics dominate the language used to describe fiscal policies and budgets in monetary terms. Factors like contribution to GDP, production outputs per hectare and export earnings are all about figures. However, in real life, evidence goes beyond figures or statistics. If developing countries swallow this notion of evidence hook line and sinker, they completely undervalue their economies.