( CNN ) -- Governments and charities have spent billions to try to wipe out poverty , but award-winning economist Esther Duflo says we really do n't know if that money has been well spent . But as a result of Duflo 's pioneering work , we may be getting some answers to that question . The Massachusetts Institute of Technology professor has led the way in showing how the scientific method can be applied to determining what policies actually work . Duflo last month won the John Bates Clark Medal , which is awarded to an American economist under the age of 40 who has made the `` most significant contribution to economic thought and knowledge . '' In her talk at the TED2010 conference in Long Beach , California , Duflo pointed out that Africa has received a great amount of development aid , but the African economies have not made a lot of progress in improving their gross domestic product . `` If we do n't know whether we are doing any good , we are not any better than the medieval doctors and their leeches . Sometimes the patient gets better , sometimes the patient dies . Is it the leeches ? Is it something else ? We do n't know . '' Read more about Esther Duflo on TED.com . In three areas , Duflo said her research techniques can help answer vital questions : . • Giving away bed nets treated with insecticide to prevent the spread of malaria works , despite fears by some that free nets would not be valued by recipients and might be used instead as fishing nets . • If you want to enhance the effectiveness of the educational system in a developing country , you can sometimes have a great impact by indirect means . For example , if the nation is one where children suffer from intestinal worms , spending $ 100 on deworming the children can be many times more effective in getting them educated than simply spending the $ 100 on paying for teachers , school meals and other school expenses . • In the Indian state of Rajasthan , Duflo found that by creating a monthly camp and giving away kilo-sized bags of lentils , there was a significant increase in the number of parents who brought their children to be immunized with potentially life-saving vaccines . Duflo said , `` It 's not the Middle Ages anymore . It 's the 21st century . And in the 20th century , randomized , controlled trials have revolutionized medicine by allowing us to distinguish between drugs that work and drugs that do n't work . And you can do the same randomized , controlled trial for social policy . You can put social innovation to the same rigorous , scientific tests that we use for drugs . ''
Esther Duflo : Le Monde utilise She says scientific method can determine which policies work . Duflo received award as most accomplished American economist under the age of 40 .