Global Imbalances and Demographic Trends

It is certainly difficult to predict the way the world will look in 20 years, but one thing is certain: most of the factors that will shape it are already at work. The demographic aging of the Western world should be the main factor behind the decline of long-term savings rates thus distorting the allocation of global savings. In this context, what impact will differences in debt levels and demographic evolutions have on savings and global investments? What policies would be most likely to implement a new balance of financial flows?