A 2019 meta-analysis of 69 studies found "that there is no aggregate relationship between natural resources and conflict." According to a 2017 review study, "while some studies support the link between resource scarcity/abundance and armed conflict, others find no or only weak links." According to one academic study, a country that is otherwise typical but has primary commodity exports around 5% of GDP has a 6% risk of conflict, but when exports are 25% of GDP the chance of conflict rises to 33%. "Ethno-political groups are more likely to resort to rebellion rather than using nonviolent means or becoming terrorists when representing regions rich in oil."