Hummels (2001) finds that inefficiencies at African ports add a cost of 8.1 per cent to the value of transactions. More efficient customs procedures are found to cause trade flows to increase by as much as 30 per cent in developing countries (Wilson et al. Similarly, cutting the number of days required to clear customs in Ethiopia by half could cause total factor productivity to increase by 18 per cent. While most NTMs are meant to address public policy concerns - both economic (such as market failures) and non-economic (e.g. to protect health, animal and plant life) - they may actually serve a protectionist purpose, whether intended or incidental. For example, the WTO registered a sharp increase in the number of countervailing measures and safeguards initiated in 2008 and 2009 as crisis-hit economies took emergency’ measures to limit the spread of systemic damage.