 The world is aging rapidly and this creates great challenges for many countries around the world because if people keep retiring at age 60 to 65 or even earlier then the number of dependents relying on each worker which is something we call the dependency ratio is going to increase and that's going to make it much harder to maintain or improve living standards. Now China like many countries has undergone a rapid demographic transition and this means that falling mortality rates and then fertility rates has led to a declining dependency ratio which has increased economic growth. But as you can see we are just at the point where these patterns are going to reverse and the dependency ratio is going to increase resulting in slower growth for the foreseeable future. The only way to reverse this grim logic is to challenge the fundamental assumption and extend working life. But how do we do that? If we can manage to increase the healthy lives of persons as life expectancy grows so that they continue working then it's actually possible to have a lower dependency rate even with population aging. Now that's not so simple because older people have to be willing and able to work at older ages and they have to be able to do so productively if employers are going to hire them. So today I want to draw on some of the recent ideas from social science research and medical research that informs this problem. And to link to the brain research theme I want to focus in particular on the real critical role that extending cognitive function at older ages plays for extending working life. And to do so I want to draw on some results from a research project that I've been involved in called the China Health and Retirement Longitudinal Study or Charles. Charles is a survey that conducted its first national baseline survey of over 17,000 people from throughout China in 2011 and 2012. These are people aged 45 and older plus their spouses. And the great thing about Charles is a publicly accessible dataset. It investigated various dimensions of well-being. You can read our summary report. And one thing we found is that cognition does indeed decline with age and that the cognitive function level of women is systematically lower than men at older ages. Now there's been very interesting work that has also shown that there are huge gaps in cognitive function across countries. A 65-year-old in China on average has the same cognitive function as an 85-year-old in the U.S. or a 55-year-old in India. What socioeconomic factors contribute to these huge gaps? Well by far the most important factor is education. Research affects how we think and it predicts a future lifetime of activities which stimulate cognitive function. Social scientists have found that when it comes to cognition you have to use it or lose it. And so social interaction and work activity are also important factors determining cognitive outcomes. Research using the Charles data has found that in China older people who participate in social activities such as playing mahjong or other games have a slower rate of cognitive decline although establishing causality is difficult. And similar findings have been found in other countries including developed countries. As when it comes to work we know that countries that have a slower decline in labor force participation are also countries where we see less of a decline in cognitive function suggesting a direct link between retirement and cognitive decline. Another important factor which is important for cognitive function is good physical and mental health and those are also important themselves for extending working life. In China we have found that 38% of the elderly have some sort of physical limitation, health limitation and 40% exhibit elevated depressive symptoms which suggests very great challenges for health improving health in China. Now what can governments do? By far the most important thing is to have pension systems that do not provide financial incentives for people to retire when both they and their employers would like to see them continue work and that means eventually eliminating mandatory retirement ages. Employers can also help extend working lives by retraining programs through work flexible work schedules, investing in worker health and changing the work environment. A BMW plant with older workers increased productivity by 7% just by introducing ergonomic equipment and making other basic changes. Earning income earning years also has other direct benefits for growth. It increases the returns to human capital investment and education in particular and increases aggregate savings because older people are now earning instead of spending. And this can create a very powerful virtual cycle which can support steady improvements in the well-being of all members of society even in a future of rapid population aging. So the question I leave you with is how can governments and businesses best support extending working lives? Thank you.