 While I'm looking at what prevents households to invest in health products that we know can save lives but are not necessarily always available, there are a whole bunch of technologies like bed nets and water filters and water purification kits that parents have a hard time investing in because they are extremely poor, they don't have access to credit and yet the international community seem to be reluctant to subsidize them all the way down to a full subsidy, so a zero price. There was this sense that if people have not paid for something they are not going to value it and there are some strong theoretical reasons to think that because typically we think the more I'm going to pay for something the more I value it. In the case of health products in poor countries this may break down because people don't have money and don't have access to a place where they can borrow so even if they value something very highly they may not be able to find the money for it and in that case charging a price may just prevent poor people to get what's really needed for them to prevent their children from dying. So I wanted to check whether it is the case that people will access a product without having to pay are not going to be using it appropriately or not going to generate the health gains that you hope for when you subsidize. What you want to do is you want to expose people to different prices and you want to see whether people who've paid more end up using it more. So we do that by having different prenatal clinics charging different prices and then seeing whether those women we can afford to buy at a higher price in the clinics where it's more expensive indeed have a higher usage rate than those who just got it for free. We don't find evidence for that we find that everybody pretty much uses it to a great extent and so that means that when you decrease the price all the way down to zero you get many more people that end up being covered with a product so sleeping at our bed net which is good for them and for their unborn children. We didn't find any evidence of people using these bed nets as bedding well or fishing nets or things that you know we've already in the press on a regular basis there was no evidence of that. People in rich countries do not have to make these daily management decisions about their environment they don't have to clean the water they don't have to think about protecting themselves from malaria. So down the road it would be much nicer if no one had to think too hard about how much money how much time to invest in the things. In the meantime it's necessary to have subsidies to improve the environment that people face but down the road the key goal should be in my view to reduce the disease burden in a massive scale and that can only happen through massive infrastructural investments by governments and by the international communities and when it comes to clean water in rich countries it has happened through governments investing in sanitation and infrastructure and as long as most people are in rural areas it's extremely costly to do that but there is now massive urbanization in Africa going on that's really a key moment to see the opportunity to set up sort of like clean and sanitary areas for people to move in rather than wait for you know slums to develop without sanitation. So to conclude if I think about rich countries and their experience it was not so individual subsidies or individual behavior that things got turned around in terms of health outcomes it was through public infrastructure investments eradicating