Bolivia has the second-largest proven natural gas reserves in South America behind Venezuela (see chart in Natural Gas section). The country’s most important exports are natural gas, minerals, and agricultural products. Earnings from natural gas exports are an important driver of Bolivia’s economic growth. In May 2006, President Evo Morales embarked on a campaign of resource nationalism, including the re-nationalization of all hydrocarbon resources and the renegotiation of export contracts with Argentina and Brazil. The impact of this campaign remains unclear: in the short-term, Bolivia has been able to secure higher prices for its natural gas exports, but foreign investment has been slow to recover to its former levels.