The problem of inequality has become so pressing that it needs coordinated global action to address it, a group of over 500 economists and scientists said on Friday. The group, which includes former Treasury Secretary and Federal Reserve Chair Janet Yellen along with French economist Thomas Piketty and Nobel Prize winner Daren Acemoglu, called in an open letter for the creation of a body akin to the UN's Intergovernmental Panel on Climate Change (IPCC) to coordinate action against what it saw