Japan boasted the developed world's youngest population in 1950, with only 4.9% of its people aged over 65. But by 2015, one in four Japanese will be elderly, making it the oldest and this will rise further to nearly one out of three in 2050. Whereas in 1950, Japan's fertility rate was 2.75 the number of children per couple, today it is 1.43 which means while today Japan's population is about 126 million, it will decline to 100 million by...