The last fifty years? The only thing that comes to mind is the incorporation of ecological theory. You could add, even though they were first put forward in the previous thirty years (but they were refined and developed, especially the first, in the 1950s and 60s)(a) the cultural criticism of capitalism of the Frankfurt School, i.e criticism of the poor quality as well as the lack of quantity (material poverty) of life under capitalism.(b) the theory of state capitalism and of a collective owning and exploiting class on the basis of them monopolising the state where the means of production are state owned.