Increasingly, governments in high income nations, such as the United States and regional blocs such as the European Union, set market-entry standards that determine the green content of supply chains, particularly for the agricultural and resource sectors, which account for the bulk of Africa's exports. Their power comes from their capacity to threaten non-compliant multinational firms with reputational damage. An alternative strategy by civil society has been to engage big firms in a collective attempt to raise standards and certify best practice.