企業有錢不投資固定資產；很多人選擇退出勞動力市場，找到工作的工資低；再加上近期所謂的新科技不過就是網上社交APP，對實體經濟有害無利，所以錢隻在股市裏折騰。
productivity growth 與 GDP 增長率正比關係，GDP 又和長期股指正比關係，所以俺長線不看好美股。
Productivity growth has been all over the board for decades, but 2016 is expected to be the first year of contraction since the 1980s. SOURCE: THE CONFERENCE BOARD
