Ever since last year, in response to the publication of Thomas Piketty's Capital in the Twenty-First Century, the hot topic in the field of economics has been inequality. Piketty's book, which argues that if left unchecked wealth will be increasingly concentrated into the already wealthy end of society, many saw the book as evidence for progressive taxes on the wealthiest members of a society. However, according to The Economist a new critique of Piketty's work is making waves among economists. A paper by MIT graduate student Matthew Rognlie argues that, since the 1970s, the only form of capital that has demonstrably increased the wealth of the wealthy is housing. With this in mind, The Economist suggests that, instead of focusing on taxation, "policy-makers should deal with the planning regulations and NIMBYism that inhibit housebuilding." Read more about Rognlie's paper at The Economist, or (for the more adventurous) read the paper for yourself here.