Let's turn now to focus on the social determinants of health with a focus beyond the immediacy of family and peers, to a set of more distal or structural social determinants of health. There are many of these that can be grouped in many different ways. I've arbitrarily grouped them into four key themes, with the next few lectures addressing each of these in turn. And, we'll focus on economic factors, human rights and gender, population displacement, and advertising and marketing. But, let's start by focusing on economic factors. We know that greater national wealth is strongly associated with better health outcomes in both sexes, with the exception of self-reported injuries, exposure to violence, and smoking. But, countries with a very low income have up to a 5 fold variation in, for example, male adolescent mortality, and a 10 fold variation in teenage birth rate, despite similar national wealth. And in the next few slides, I'll show these on a graph. This fact that this extent of variation suggests that cultural, religious or other social factors strongly moderate the effects of structural determinants, such as wealth. Let's look at this in more detail on this graph. This graph is taken from the second paper of the recent Lancet series on adolescent health led by Russell Viner and colleagues. And you can see on the horizontal axis is gross domestic product per person calibrated to a thousand US dollars. On the vertical axis is deaths per 100,000 population of 15 to 19 year olds. And as can be seen with this line that I've drawn here, which groups countries with the same, in this case, low gross domestic product. You can see there's more than a five fold difference in mortality, for the same level of GDP. Similarly, in the next graph, where again, we've plotted gross domestic product on the horizontal axis, and this time, births per 1,000 girls, ages 15 to 39 years on the vertical axis, which is grouping countries with the same level of GDP, we can see up to a tenfold difference, a highly dramatic difference in birth rate. What this means is that it's more than just the level of income that matters. Countries have political, economic and social systems that produce more or less income inequality. Those countries with greater income inequality have poorer health across all outcomes. Again, with the exceptions of reported injuries, exposure to violence and smoking rates. And the associations we see between national wealth, inequality and adolescent health probably relate both to cumulative effects that persist from earlier childhood, together with contemporary or pathway effects that take place during adolescence itself. Now we know that wealth generated by national economic development is highly beneficial for adolescents. But their health is vulnerable to income inequalities generated by development particularly where rapid urban development and urbanisation create large populations of deprived, marginalised and displaced young people. And particularly when unemployment is high. Employment is a mechanism through which young people share in the wealth of a society. Long-term unemployment or underemployment among young people carries a heavy price. Young people who struggle to find work often suffer permanent scarring of their future earning power with a potential for profound impacts on their health, especially on mental health, including suicide and violence related mortality. The particular challenge is that the young are especially hard hit when economic times are tough. For example, 15 to 24 year olds are nearly 3 times as likely to be unemployed than older adult workers. And while 15 to 24 year olds comprise 17% of the population, they constitute 40% of the unemployed. Now, the International Labor Organisation estimated the global unemployment rate among 15 to 24 year olds to be 12.6% in 2013, equating to 73 million young people jobless worldwide. This compares threefold higher to an estimated global unemployment rate at that time of 4.5%. However, interestingly, the World Economic Forum estimated much higher rates, suggesting that about 30% of the world's 15 to 24 year olds are not in school and not employed. There is less debate about where the highest rates of unemployment are, and this is namely in the Middle East, North Africa and Europe where youth unemployment rates have skyrocketed since 2008. For instance, in developed economies and the European Union, joblessness among young people has ballooned by nearly 25% in the past five years, reaching a devastating 18.1% overall. In the meantime, Europe is seeing a greater proportion of its youth being forced to take jobs they are overqualified for, or to take part time or temporary work. A phenomena that is seen the world over. Levels of informal employment among young people are soaring, and young people are finding it ever more difficult to find jobs that match their skills and education. Not only does this mean that society is missing out on new skills from highly qualified young people, but it also means that the overeducated young are preventing less qualified and less skilled young people from entering the workforce. In this graph, here, you can see that percent change in youth unemployment in European countries over really a very short period of time, 2008 to 2013. And as you can see, those highest increases in the rate of unemployment are in Greece, Spain and Portugal. Professor Sir Michael Marmot, professor of epidemiology and public health at University College London, is a global expert in inequalities in health and their causes. Most recently chairing a review on the social determinants of health in Europe, that was commissioned by the World Health Organisation. He used the most powerful of language by referring to the growing rates of youth unemployment in Europe as a public health emergency. But it is not just public health advocates who share this same view. Dr. Ken Henry is an economist and past Secretary of the Department of Treasury in Australia. He suggested that, young people that are not in the education system and who are denied work are deprived of the freedom to lead a life that they would otherwise choose. And he argued that this is a threat to their human rights.