Taking into account the effectiveness of aid organizations is important because organizations have different skills to help people. Donors who want to maximize the impact of their money can now rely on a large number of studies to compare the effectiveness of various interventions and aid organizations. Over 3 billion people still live in extreme poverty (less than 2 EUR / day). Helping these people is relatively inexpensive. For example, with a payment of less than 0,50 EUR to the Schistosomiasis Control Initiative, a child can be cured of parasitic worms, or with less than 5 EUR, the Against Malaria Foundation can protect two people from malaria for five years with a durable mosquito net.