Another May Day

Karl Marx's birthday. There is a spate of articles about Karl Marx. It seems to me that Marx's critique of capitalism is incisive but his ideas towards solutions are not. Among the several article, I noticed one by Eric Posner and Glen Weyl which combines some ideas of Marx with those of Henry George and some new suggestions, The real villain behind our new gilded age  "But the true villain would be familiar to anyone who lived through the previous one: market (that is, monopoly) power." 
There is An interview with Glen  in which he spells out some of the ideas. One of them: "The idea of the proposal is that you would self-assess the value of all major private property you own, aside from personal effects. For all significant private property, you would self-assess the value, you would pay tax on the assessed value, and then you would have to stand ready to sell that property to anybody who wants to purchase it at that price.”
The new book by Eric Posner and Glen Wel to be out soon has couple of sections available at Google books Radical Markets: Uprooting Capitalism and Democracy for a Just Society 
The book seems very controversial already.
A review and comments at Marginal Revolution.