What do you buy the nation that already seems to have everything? That is the question facing Japanese Prime Minister Shinzo Abe as he aims to spend more than $100 billion on infrastructure in the next 15 months to help revive his country's economy. But with its gleaming bullet trains, jungles of elevated highways and strings of man-made islands, ultra-modern Japan doesn't appear to want for much. "We cannot simply continue to build roads and infrastructure the way we used to at a time when the population is ageing and shrinking," says Takayoshi Igarashi, a public policy professor at Japan's Hosei University ... (full story)